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Biosensors
Volume 14
Issue 8
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Biosensors, Volume 14, Issue 8 (August 2024) – 49 articles

Cover Story (view full-size image): Intracellular bacterial pathogens can evade immune defenses by residing within host immune cells, such as macrophages, creating infection reservoirs that hinder treatment. Changes in macrophage cell surface glycosylation during infection present a potential detection strategy, though glycan diversity complicates profiling. A boronic acid-based pH-responsive polymer sensor array was created to detect bacterial infections in macrophages by identifying distinct glycosylation signatures. This sensor rapidly differentiates between bacterial species within minutes, offering a new tool for diagnostic and screening applications. View this paper
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29 pages, 9259 KiB  
Review
Recent Advances in Nanomaterials for Modulation of Stem Cell Differentiation and Its Therapeutic Applications
by Chang-Dae Kim, Kyeong-Mo Koo, Hyung-Joo Kim and Tae-Hyung Kim
Biosensors 2024, 14(8), 407; https://doi.org/10.3390/bios14080407 - 22 Aug 2024
Cited by 6 | Viewed by 3644
Abstract
Challenges in directed differentiation and survival limit the clinical use of stem cells despite their promising therapeutic potential in regenerative medicine. Nanotechnology has emerged as a powerful tool to address these challenges and enable precise control over stem cell fate. In particular, nanomaterials [...] Read more.
Challenges in directed differentiation and survival limit the clinical use of stem cells despite their promising therapeutic potential in regenerative medicine. Nanotechnology has emerged as a powerful tool to address these challenges and enable precise control over stem cell fate. In particular, nanomaterials can mimic an extracellular matrix and provide specific cues to guide stem cell differentiation and proliferation in the field of nanotechnology. For instance, recent studies have demonstrated that nanostructured surfaces and scaffolds can enhance stem cell lineage commitment modulated by intracellular regulation and external stimulation, such as reactive oxygen species (ROS) scavenging, autophagy, or electrical stimulation. Furthermore, nanoframework-based and upconversion nanoparticles can be used to deliver bioactive molecules, growth factors, and genetic materials to facilitate stem cell differentiation and tissue regeneration. The increasing use of nanostructures in stem cell research has led to the development of new therapeutic approaches. Therefore, this review provides an overview of recent advances in nanomaterials for modulating stem cell differentiation, including metal-, carbon-, and peptide-based strategies. In addition, we highlight the potential of these nano-enabled technologies for clinical applications of stem cell therapy by focusing on improving the differentiation efficiency and therapeutics. We believe that this review will inspire researchers to intensify their efforts and deepen their understanding, thereby accelerating the development of stem cell differentiation modulation, therapeutic applications in the pharmaceutical industry, and stem cell therapeutics. Full article
(This article belongs to the Special Issue Functional Materials for Biosensing Applications)
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21 pages, 3174 KiB  
Article
MLS-Net: An Automatic Sleep Stage Classifier Utilizing Multimodal Physiological Signals in Mice
by Chengyong Jiang, Wenbin Xie, Jiadong Zheng, Biao Yan, Junwen Luo and Jiayi Zhang
Biosensors 2024, 14(8), 406; https://doi.org/10.3390/bios14080406 - 22 Aug 2024
Cited by 1 | Viewed by 1742
Abstract
Over the past decades, feature-based statistical machine learning and deep neural networks have been extensively utilized for automatic sleep stage classification (ASSC). Feature-based approaches offer clear insights into sleep characteristics and require low computational power but often fail to capture the spatial–temporal context [...] Read more.
Over the past decades, feature-based statistical machine learning and deep neural networks have been extensively utilized for automatic sleep stage classification (ASSC). Feature-based approaches offer clear insights into sleep characteristics and require low computational power but often fail to capture the spatial–temporal context of the data. In contrast, deep neural networks can process raw sleep signals directly and deliver superior performance. However, their overfitting, inconsistent accuracy, and computational cost were the primary drawbacks that limited their end-user acceptance. To address these challenges, we developed a novel neural network model, MLS-Net, which integrates the strengths of neural networks and feature extraction for automated sleep staging in mice. MLS-Net leverages temporal and spectral features from multimodal signals, such as EEG, EMG, and eye movements (EMs), as inputs and incorporates a bidirectional Long Short-Term Memory (bi-LSTM) to effectively capture the spatial–temporal nonlinear characteristics inherent in sleep signals. Our studies demonstrate that MLS-Net achieves an overall classification accuracy of 90.4% and REM state precision of 91.1%, sensitivity of 84.7%, and an F1-Score of 87.5% in mice, outperforming other neural network and feature-based algorithms in our multimodal dataset. Full article
(This article belongs to the Special Issue Implantable, Wireless Biosensors and Biodevices for Neuroscience Research)
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11 pages, 7830 KiB  
Article
Ultrasoft Long-Lasting Reusable Hydrogel-Based Sensor Patch for Biosignal Recording
by Alexandre Tessier, Shuyun Zhuo and Shideh Kabiri Ameri
Biosensors 2024, 14(8), 405; https://doi.org/10.3390/bios14080405 - 22 Aug 2024
Cited by 2 | Viewed by 1679
Abstract
Here, we report an ultrasoft extra long-lasting, reusable hydrogel-based sensor that enables high-quality electrophysiological recording with low-motion artifacts. The developed sensor can be used and stored in an ambient environment for months before being reused. The developed sensor is made of a self-adhesive [...] Read more.
Here, we report an ultrasoft extra long-lasting, reusable hydrogel-based sensor that enables high-quality electrophysiological recording with low-motion artifacts. The developed sensor can be used and stored in an ambient environment for months before being reused. The developed sensor is made of a self-adhesive electrical-conductivity-enhanced ultrasoft hydrogel mounted in an Ecoflex-based frame. The hydrogel’s conductivity was enhanced by incorporating polypyrrole (PPy), resulting in a conductivity of 0.25 S m−1. Young’s modulus of the sensor is only 12.9 kPa, and it is stretchable up to 190%. The sensor was successfully used for electrocardiography (ECG) and electromyography (EMG). Our results indicate that using the developed hydrogel-based sensor, the signal-to-noise ratio of recorded electrophysiological signals was improved in comparison to that when medical-grade silver/silver chloride (Ag/AgCl) wet gel electrodes were used (33.55 dB in comparison to 22.16 dB). Due to the ultra-softness, high stretchability, and self-adhesion of the developed sensor, it can conform to the skin and, therefore, shows low susceptibility to motion. In addition, the sensor shows no sign of irritation or allergic reaction, which usually occurs after long-term wearing of medical-grade Ag/AgCl wet gel electrodes on the skin. Further, the sensor is fabricated using a low-cost and scalable fabrication process. Full article
(This article belongs to the Section Wearable Biosensors)
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8 pages, 940 KiB  
Communication
Applying a Fluorescence Polarization Assay for Detection of Brucellosis in Animals Using the Fluorescently Labeled Synthetic Oligosaccharides as Biosensing Tracer
by Liliya I. Mukhametova, Dmitry O. Zherdev, Sergei A. Eremin, Anton N. Kuznetsov, Viktor I. Yudin, Oleg D. Sclyarov, Olesia V. Babicheva, Anton V. Motorygin, Yury E. Tsvetkov, Vadim B. Krylov and Nikolay E. Nifantiev
Biosensors 2024, 14(8), 404; https://doi.org/10.3390/bios14080404 - 21 Aug 2024
Cited by 3 | Viewed by 1597
Abstract
Brucellosis in animals is an infectious disease caused by bacteria of the genus Brucella. Known methods for diagnosing brucellosis face some challenges, due to the difficulties in isolating and standardizing the natural brucellosis antigen. In this work, we investigated the possibility of [...] Read more.
Brucellosis in animals is an infectious disease caused by bacteria of the genus Brucella. Known methods for diagnosing brucellosis face some challenges, due to the difficulties in isolating and standardizing the natural brucellosis antigen. In this work, we investigated the possibility of using the fluorescence polarization assay (FPA) with synthetic glycoconjugate biosensing tracers to detect antibodies against Brucella as a new methodology for diagnosing brucellosis. Based on the received results, the synthetic fluorescein-labeled trisaccharide tracer is most effective for Brucellosis detection. This tracer is structurally related to the immune determinant fragment of the Brucella LPS buildup of N-formyl-d-perosamine units, connected via α-(1→3)-linkage at the non-reducing end and α-(1→2)-linkage at the reducing end. The sensitivity and specificity in the case of the use of trisaccharide tracer 3b were 71% and 100% (Yuden’s method) and 87% and 88% (Euclidean method), respectively, which is comparable with the diagnostic efficiency of traditionally used serological methods, such as the agglutination test (AT), complement fixation test (CFT), and Rose Bengal test (RBT). Given the known advantages of FPA (e.g., speed, compactness of the equipment, and standard reagents) and the increased specificity of the developed test system, it would be appropriate to consider its widespread use for the diagnosis of brucellosis in animals, including rapid testing in the field. Full article
(This article belongs to the Special Issue Immunosensors: Design and Applications)
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13 pages, 3302 KiB  
Article
Solid-Phase Electrochemiluminescence Enzyme Electrodes Based on Nanocage Arrays for Highly Sensitive Detection of Cholesterol
by Xinying Ma, Zhe Zhang, Yanyan Zheng and Jiyang Liu
Biosensors 2024, 14(8), 403; https://doi.org/10.3390/bios14080403 - 21 Aug 2024
Cited by 14 | Viewed by 1353
Abstract
The convenient and sensitive detection of metabolites is of great significance for understanding human health status and drug development. Solid-phase electrochemiluminescence (ECL) enzyme electrodes show great potential in metabolite detection based on the enzyme-catalyzed reaction product hydrogen peroxide (H2O2). [...] Read more.
The convenient and sensitive detection of metabolites is of great significance for understanding human health status and drug development. Solid-phase electrochemiluminescence (ECL) enzyme electrodes show great potential in metabolite detection based on the enzyme-catalyzed reaction product hydrogen peroxide (H2O2). Herein, a solid-phase ECL enzyme sensor was fabricated based on a confined emitter and an immobilized enzyme using electrostatic nanocage array, constructing a platform for the sensitive detection of cholesterol. The electrostatic cage nanochannel consists of a bipolar and bilayer vertically aligned mesoporous silica film (bp-VMSF). The upper layer of bp-VMSF is an amino-modified, positively charged VMSF (p-VMSF), and the lower layer is a negatively charged VMSF (n-VMSF). The most commonly used ECL probe tris(bipyridine)ruthenium(II) (Ru(bpy)32+) is fixed in n-VMSF by electrostatic adsorption from n-VMSF and electrostatic repulsion from the upper p-VMSF, generating significantly enhanced and stable ECL signals. The successful preparation of the electrostatic cage was characterized by scanning electron microscopy (SEM) and electrochemical methods. After amino groups on the outer surface of bp-VMSF were derivatized with aldehyde, cholesterol oxidase (ChOx) molecules were covalently immobilized. The successful construction of the enzyme electrode was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). When the corresponding enzyme substrate, cholesterol, was present in the solution, the ECL signal of Ru(bpy)32+ was quenched by the enzyme-catalyzed reaction product H2O2, enabling the high-sensitivity detection of cholesterol. The linear range for detecting cholesterol was from 0.05 mM to 5.0 mM, with a limit of detection (LOD) of 1.5 μM. Full article
(This article belongs to the Special Issue Electrochemical and Fluorescent Biosensors: Novel Strategies, Methods, and Materials II)
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17 pages, 6095 KiB  
Article
A Bacteriophage Protein-Based Impedimetric Electrochemical Biosensor for the Detection of Campylobacter jejuni
by Baviththira Suganthan, Ashley M. Rogers, Clay S. Crippen, Hamid Asadi, Or Zolti, Christine M. Szymanski and Ramaraja P. Ramasamy
Biosensors 2024, 14(8), 402; https://doi.org/10.3390/bios14080402 - 21 Aug 2024
Cited by 2 | Viewed by 1821
Abstract
Campylobacter jejuni is a common foodborne pathogen found in poultry that can cause severe life-threatening illnesses in humans. It is important to detect this pathogen in food to manage foodborne outbreaks. This study reports a novel impedimetric phage protein-based biosensor to detect C. [...] Read more.
Campylobacter jejuni is a common foodborne pathogen found in poultry that can cause severe life-threatening illnesses in humans. It is important to detect this pathogen in food to manage foodborne outbreaks. This study reports a novel impedimetric phage protein-based biosensor to detect C. jejuni NCTC 11168 at 100 CFU/mL concentrations using a genetically engineered receptor-binding phage protein, FlaGrab, as a bioreceptor. The electrochemical impedance spectroscopy (EIS) technique was employed to measure changes in resistance upon interaction with C. jejuni. The sensitivity of the phage protein-immobilized electrode was assessed using the various concentrations of C. jejuni NCTC 11168 ranging from 102–109 colony forming units (CFU)/mL). The change transfer resistance of the biosensor increased with increasing numbers of C. jejuni NCTC 11168 cells. The detection limit was determined to be approximately 103 CFU/mL in the buffer and 102 CFU/mL in the ex vivo samples. Salmonella enterica subsp. enterica serotype Typhimurium-291RH and Listeria monocytogenes Scott A were used as nontarget bacterial cells to assess the specificity of the developed biosensor. Results showed that the developed biosensor was highly specific toward the target C. jejuni NCTC 11168, as no signal was observed for the nontarget bacterial cells. Full article
(This article belongs to the Special Issue Biosensors for Food Safety)
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14 pages, 2485 KiB  
Article
Centrifugal Microfluidic Cell Culture Platform for Physiologically Relevant Virus Infection Studies: A Case Study with HSV-1 Infection of Periodontal Cells
by Juliane Fjelrad Christfort, Morgane Ortis, Hau Van Nguyen, Robert Marsault and Alain Doglio
Biosensors 2024, 14(8), 401; https://doi.org/10.3390/bios14080401 - 20 Aug 2024
Viewed by 1514
Abstract
Static well plates remain the gold standard to study viral infections in vitro, but they cannot accurately mimic dynamic viral infections as they occur in the human body. Therefore, we established a dynamic cell culture platform, based on centrifugal microfluidics, to study viral [...] Read more.
Static well plates remain the gold standard to study viral infections in vitro, but they cannot accurately mimic dynamic viral infections as they occur in the human body. Therefore, we established a dynamic cell culture platform, based on centrifugal microfluidics, to study viral infections in perfusion. To do so, we used human primary periodontal dental ligament (PDL) cells and herpes simplex virus-1 (HSV-1) as a case study. By microscopy, we confirmed that the PDL cells efficiently attached and grew in the chip. Successful dynamic viral infection of perfused PDL cells was monitored using fluorescent imaging and RT-qPCR-based experiments. Remarkably, viral infection in flow resulted in a gradient of HSV-1-infected cells gradually decreasing from the cell culture chamber entrance towards its end. The perfusion of acyclovir in the chip prevented HSV-1 spreading, demonstrating the usefulness of such a platform for monitoring the effects of antiviral drugs. In addition, the innate antiviral response of PDL cells, measured by interferon gene expression, increased significantly over time in conventional static conditions compared to the perfusion model. These results provide evidence suggesting that dynamic viral infections differ from conventional static infections, which highlights the need for more physiologically relevant in vitro models to study viral infections. Full article
(This article belongs to the Section Nano- and Micro-Technologies in Biosensors)
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12 pages, 4479 KiB  
Article
Capillary Flow-Based One-Minute Quantification of Amyloid Proteolysis
by Taeha Lee, Da Yeon Cheong, Kang Hyun Lee, Jae Hyun You, Jinsung Park and Gyudo Lee
Biosensors 2024, 14(8), 400; https://doi.org/10.3390/bios14080400 - 19 Aug 2024
Viewed by 1479
Abstract
Quantifying the formation and decomposition of amyloid is a crucial issue in the development of new drugs and therapies for treating amyloidosis. The current technologies for grasping amyloid formation and decomposition include fluorescence analysis using thioflavin-T, secondary structure analysis using circular dichroism, and [...] Read more.
Quantifying the formation and decomposition of amyloid is a crucial issue in the development of new drugs and therapies for treating amyloidosis. The current technologies for grasping amyloid formation and decomposition include fluorescence analysis using thioflavin-T, secondary structure analysis using circular dichroism, and image analysis using atomic force microscopy or transmission electron microscopy. These technologies typically require spectroscopic devices or expensive nanoscale imaging equipment and involve lengthy analysis, which limits the rapid screening of amyloid-degrading drugs. In this study, we introduce a technology for rapidly assessing amyloid decomposition using capillary flow-based paper (CFP). Amyloid solutions exhibit gel-like physical properties due to insoluble denatured polymers, resulting in a shorter flow distance on CFP compared to pure water. Experimental conditions were established to consistently control the flow distance based on a hen-egg-white lysozyme amyloid solution. It was confirmed that as amyloid is decomposed by trypsin, the flow distance increases on the CFP. Our method is highly useful for detecting changes in the gel properties of amyloid solutions within a minute, and we anticipate its use in the rapid, large-scale screening of anti-amyloid agents in the future. Full article
(This article belongs to the Special Issue Advances in Microfluidics: Transforming Detection and Quantification of Disease Biomarkers and Target Organisms)
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12 pages, 14201 KiB  
Article
Development of Novel Surface-Enhanced Raman Spectroscopy-Based Biosensors by Controlling the Roughness of Gold/Alumina Platforms for Highly Sensitive Detection of Pyocyanin Secreted from Pseudomonas aeruginosa
by Waleed A. El-Said, Tamer S. Saleh, Abdullah Saad Al-Bogami, Mohmmad Younus Wani and Jeong-woo Choi
Biosensors 2024, 14(8), 399; https://doi.org/10.3390/bios14080399 - 19 Aug 2024
Cited by 1 | Viewed by 1544
Abstract
Pyocyanin is considered a maker of Pseudomonas aeruginosa (P. aeruginosa) infection. Pyocyanin is among the toxins released by the P. aeruginosa bacteria. Therefore, the development of a direct detection of PYO is crucial due to its importance. Among the different optical [...] Read more.
Pyocyanin is considered a maker of Pseudomonas aeruginosa (P. aeruginosa) infection. Pyocyanin is among the toxins released by the P. aeruginosa bacteria. Therefore, the development of a direct detection of PYO is crucial due to its importance. Among the different optical techniques, the Raman technique showed unique advantages because of its fingerprint data, no sample preparation, and high sensitivity besides its ease of use. Noble metal nanostructures were used to improve the Raman response based on the surface-enhanced Raman scattering (SERS) technique. Anodic metal oxide attracts much interest due to its unique morphology and applications. The porous metal structure provides a large surface area that could be used as a hard template for periodic nanostructure array fabrication. Porous shapes and sizes could be controlled by controlling the anodization parameters, including the anodization voltage, current, temperature, and time, besides the metal purity and the electrolyte type/concentration. The anodization of aluminum foil results in anodic aluminum oxide (AAO) formation with different roughness. Here, we will use the roughness as hotspot centers to enhance the Raman signals. Firstly, a thin film of gold was deposited to develop gold/alumina (Au/AAO) platforms and then applied as SERS-active surfaces. The morphology and roughness of the developed substrates were investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. The Au/AAO substrates were used for monitoring pyocyanin secreted from Pseudomonas aeruginosa microorganisms based on the SERS technique. The results showed that the roughness degree affects the enhancement efficiency of this sensor. The high enhancement was obtained in the case of depositing a 30 nm layer of gold onto the second anodized substrates. The developed sensor showed high sensitivity toward pyocyanin with a limit of detection of 96 nM with a linear response over a dynamic range from 1 µM to 9 µM. Full article
(This article belongs to the Special Issue The Emerging Techniques in Biosensors and Bioelectronics)
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16 pages, 2988 KiB  
Article
Imaging Diffractometric Biosensors for Label-Free, Multi-Molecular Interaction Analysis
by Cornelia Reuter, Walter Hauswald, Sindy Burgold-Voigt, Uwe Hübner, Ralf Ehricht, Karina Weber and Juergen Popp
Biosensors 2024, 14(8), 398; https://doi.org/10.3390/bios14080398 - 17 Aug 2024
Cited by 1 | Viewed by 1370
Abstract
Biosensors are used for the specific and sensitive detection of biomolecules. In conventional approaches, the suspected target molecules are bound to selected capture molecules and successful binding is indicated by additional labelling to enable optical readout. This labelling requires additional processing steps tailored [...] Read more.
Biosensors are used for the specific and sensitive detection of biomolecules. In conventional approaches, the suspected target molecules are bound to selected capture molecules and successful binding is indicated by additional labelling to enable optical readout. This labelling requires additional processing steps tailored to the application. While numerous label-free interaction assays exist, they often compromise on detection characteristics. In this context, we introduce a novel diffractometric biosensor, comprising a diffractive biosensor chip and an associated optical reader assembly. This innovative system can capture an entire assay, detecting various types of molecules in a label-free manner and present the results within in a single, comprehensive image. The applicability of the biosensor is assessed for the detection of viral DNA as well as proteins directly in human plasma, investigating different antigens. In our experiments, we achieve a detection limit of 4.2 pg/mm², which is comparable to other label-free optical biosensors. The simplicity and robustness of the method make it a compelling option for advancing biosensing technologies. This work contributes to the development of an imaging diffractometric biosensor with the potential for multiple applications in molecular interaction analysis. Full article
(This article belongs to the Section Optical and Photonic Biosensors)
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16 pages, 9690 KiB  
Article
Multiwavelength Photoacoustic Doppler Flowmetry of Living Microalgae Cells
by Tayyab Farooq, Xiuru Wu, Sheng Yan and Hui Fang
Biosensors 2024, 14(8), 397; https://doi.org/10.3390/bios14080397 - 16 Aug 2024
Cited by 1 | Viewed by 1464
Abstract
Photoacoustics can provide a direct measurement of light absorption by microalgae depending on the photosynthesis pigment within them. In this study, we have performed photoacoustic flowmetry on living microalgae cells to measure their flow characteristics, which include flow speed, flow angle, flow direction, [...] Read more.
Photoacoustics can provide a direct measurement of light absorption by microalgae depending on the photosynthesis pigment within them. In this study, we have performed photoacoustic flowmetry on living microalgae cells to measure their flow characteristics, which include flow speed, flow angle, flow direction, and, more importantly, the photoacoustic absorption spectrum, all by observing the photoacoustic Doppler power spectra during their flowing state. A supercontinuum pulsed laser with a high repetition frequency is used as the light source: through intensity modulation at a specified frequency, it can provide wavelength-selectable excitation of a photoacoustic signal centered around this frequency. Our approach can be useful to simultaneously measure the flow characteristics of microalgae and easily discriminate their different species with high accuracy in both static and dynamic states, thus facilitating the study of their cultivation and their role in our ecosystem. Full article
(This article belongs to the Special Issue Waveguide Biosensors)
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18 pages, 3089 KiB  
Article
Surface Electromyography-Based Recognition of Electronic Taste Sensations
by Asif Ullah, Fengqi Zhang, Zhendong Song, You Wang, Shuo Zhao, Waqar Riaz and Guang Li
Biosensors 2024, 14(8), 396; https://doi.org/10.3390/bios14080396 - 16 Aug 2024
Cited by 2 | Viewed by 1602
Abstract
Taste sensation recognition is a core for taste-related queries. Most prior research has been devoted to recognizing the basic taste sensations using the Brain–Computer Interface (BCI), which includes EEG, MEG, EMG, and fMRI. This research aims to recognize electronic taste (E-Taste) sensations based [...] Read more.
Taste sensation recognition is a core for taste-related queries. Most prior research has been devoted to recognizing the basic taste sensations using the Brain–Computer Interface (BCI), which includes EEG, MEG, EMG, and fMRI. This research aims to recognize electronic taste (E-Taste) sensations based on surface electromyography (sEMG). Silver electrodes with platinum plating of the E-Taste device were placed on the tongue’s tip to stimulate various tastes and flavors. In contrast, the electrodes of the sEMG were placed on facial muscles to collect the data. The dataset was organized and preprocessed, and a random forest classifier was applied, giving a five-fold accuracy of 70.43%. The random forest classifier was used on each participant dataset individually and in groups, providing the highest accuracy of 84.79% for a single participant. Moreover, various feature combinations were extracted and acquired 72.56% accuracy after extracting eight features. For a future perspective, this research offers guidance for electronic taste recognition based on sEMG. Full article
(This article belongs to the Section Biosensor and Bioelectronic Devices)
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13 pages, 3413 KiB  
Article
A Miniature Modular Fluorescence Flow Cytometry System
by Shaoqi Huang, Jiale Li, Li Wei, Lulu Zheng, Zheng Shi, Shiwei Guo, Bo Dai, Dawei Zhang and Songlin Zhuang
Biosensors 2024, 14(8), 395; https://doi.org/10.3390/bios14080395 - 16 Aug 2024
Viewed by 1434
Abstract
Fluorescence flow cytometry is a powerful instrument to distinguish cells or particles labelled with high-specificity fluorophores. However, traditional flow cytometry is complex, bulky, and inconvenient for users to adjust fluorescence channels. In this paper, we present a modular fluorescence flow cytometry (M-FCM) system [...] Read more.
Fluorescence flow cytometry is a powerful instrument to distinguish cells or particles labelled with high-specificity fluorophores. However, traditional flow cytometry is complex, bulky, and inconvenient for users to adjust fluorescence channels. In this paper, we present a modular fluorescence flow cytometry (M-FCM) system in which fluorescence channels can be flexibly arranged. Modules for particle focusing and fluorescence detection were developed. After hydrodynamical focusing, the cells were measured in the detection modules, which were integrated with in situ illumination and fluorescence detection. The signal-to-noise ratio of the detection reached to 33.2 dB. The crosstalk among the fluorescence channels was eliminated. The M-FCM system was applied to evaluate cell viability in drug screening, agreeing well with the commercial cytometry. The modular cytometry presents several outstanding features: flexibility in setting fluorescence channels, cost efficiency, compact construction, ease of operation, and the potential to upgrade for multifunctional measurements. The modular cytometry provides a multifunctional platform for various biophysical measurements, e.g., electrical impedance and refractive-index detection. The proposed work paves an innovative avenue for the multivariate analysis of cellular characteristics. Full article
(This article belongs to the Special Issue Advanced Microfluidic Devices and Lab-on-Chip (Bio)sensors)
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15 pages, 2388 KiB  
Article
Digitalization of Enzyme-Linked Immunosorbent Assay with Graphene Field-Effect Transistors (G-ELISA) for Portable Ferritin Determination
by Melody L. Candia, Esteban Piccinini, Omar Azzaroni and Waldemar A. Marmisollé
Biosensors 2024, 14(8), 394; https://doi.org/10.3390/bios14080394 - 16 Aug 2024
Viewed by 1794
Abstract
Herein, we present a novel approach to quantify ferritin based on the integration of an Enzyme-Linked Immunosorbent Assay (ELISA) protocol on a Graphene Field-Effect Transistor (gFET) for bioelectronic immunosensing. The G-ELISA strategy takes advantage of the gFET inherent capability of detecting pH changes [...] Read more.
Herein, we present a novel approach to quantify ferritin based on the integration of an Enzyme-Linked Immunosorbent Assay (ELISA) protocol on a Graphene Field-Effect Transistor (gFET) for bioelectronic immunosensing. The G-ELISA strategy takes advantage of the gFET inherent capability of detecting pH changes for the amplification of ferritin detection using urease as a reporter enzyme, which catalyzes the hydrolysis of urea generating a local pH increment. A portable field-effect transistor reader and electrolyte-gated gFET arrangement are employed, enabling their operation in aqueous conditions at low potentials, which is crucial for effective biological sample detection. The graphene surface is functionalized with monoclonal anti-ferritin antibodies, along with an antifouling agent, to enhance the assay specificity and sensitivity. Markedly, G-ELISA exhibits outstanding sensing performance, reaching a lower limit of detection (LOD) and higher sensitivity in ferritin quantification than unamplified gFETs. Additionally, they offer rapid detection, capable of measuring ferritin concentrations in approximately 50 min. Because of the capacity of transistor miniaturization, our innovative G-ELISA approach holds promise for the portable bioelectronic detection of multiple biomarkers using a small amount of the sample, which would be a great advancement in point–of–care testing. Full article
(This article belongs to the Special Issue Current Advance in Transistor-Based Biosensors for Diagnostics)
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8 pages, 1877 KiB  
Communication
Single-Nanoparticle Electrochemical Collision for Monitoring Self-Assembly of Thiol Molecules on Au Nanoparticles
by Yiyan Bai
Biosensors 2024, 14(8), 393; https://doi.org/10.3390/bios14080393 - 15 Aug 2024
Cited by 1 | Viewed by 1325
Abstract
A precise understanding of the self-assembly kinetics of small molecules on nanoparticles (NPs) can give greater control over the size and architecture of the functionalized NPs. Herein, a single-nanoparticle electrochemical collision (SNEC)-based method was developed to monitor the self-assembly processes of 6-mercapto-1-hexanol (6-MCH) [...] Read more.
A precise understanding of the self-assembly kinetics of small molecules on nanoparticles (NPs) can give greater control over the size and architecture of the functionalized NPs. Herein, a single-nanoparticle electrochemical collision (SNEC)-based method was developed to monitor the self-assembly processes of 6-mercapto-1-hexanol (6-MCH) and 1-hexanethiol (MCH) on Au NPs at the single-particle level, and to investigate the self-assembly kinetics exactly. Results showed that the self-assembly processes of both consisted of rapid adsorption and slow recombination. However, the adsorption rate of MCH was significantly lower than that of 6-MCH due to the poorer polarity. Also noteworthy is that the rapid adsorption of 6-MCH on Au NPs conformed to the Langmuir model of diffusion control. Hence, the proposed SNEC-based method could serve as a complementary method to research the self-assembly mechanism of functionalized NPs. Full article
(This article belongs to the Special Issue Advances in Plasmonic Biosensing Technology)
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15 pages, 4445 KiB  
Article
Automated Uniform Spheroid Generation Platform for High Throughput Drug Screening Process
by Kelvin C. C. Pong, Yuen Sze Lai, Roy Chi Hang Wong, Alan Chun Kit Lee, Sam C. T. Chow, Jonathan C. W. Lam, Ho Pui Ho and Clarence T. T. Wong
Biosensors 2024, 14(8), 392; https://doi.org/10.3390/bios14080392 - 15 Aug 2024
Viewed by 1682
Abstract
Three-dimensional (3D) spheroid models are crucial for cancer research, offering more accurate insights into tumour biology and drug responses than traditional 2D cell cultures. However, inconsistent and low-throughput spheroid production has hindered their application in drug screening. Here, we present an automated high-throughput [...] Read more.
Three-dimensional (3D) spheroid models are crucial for cancer research, offering more accurate insights into tumour biology and drug responses than traditional 2D cell cultures. However, inconsistent and low-throughput spheroid production has hindered their application in drug screening. Here, we present an automated high-throughput platform for a spheroid selection, fabrication, and sorting system (SFSS) to produce uniform gelatine-encapsulated spheroids (GESs) with high efficiency. SFSS integrates advanced imaging, analysis, photo-triggered fabrication, and microfluidic sorting to precisely control spheroid size, shape, and viability. Our data demonstrate that our SFSS can produce over 50 GESs with consistent size and circularity in 30 min with over 97% sorting accuracy while maintaining cell viability and structural integrity. We demonstrated that the GESs can be used for drug screening and potentially for various assays. Thus, the SFSS could significantly enhance the efficiency of generating uniform spheroids, facilitating their application in drug development to investigate complex biological systems and drug responses in a more physiologically relevant context. Full article
(This article belongs to the Special Issue Innovative Strategies for Cancer Biosensing)
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14 pages, 1032 KiB  
Review
Needle-Shaped Biosensors for Precision Diagnoses: From Benchtop Development to In Vitro and In Vivo Applications
by Ruier Xue, Fei Deng, Tianruo Guo, Alexander Epps, Nigel H. Lovell and Mohit N. Shivdasani
Biosensors 2024, 14(8), 391; https://doi.org/10.3390/bios14080391 - 13 Aug 2024
Viewed by 2252
Abstract
To achieve the accurate recognition of biomarkers or pathological characteristics within tissues or cells, in situ detection using biosensor technology offers crucial insights into the nature, stage, and progression of diseases, paving the way for enhanced precision in diagnostic approaches and treatment strategies. [...] Read more.
To achieve the accurate recognition of biomarkers or pathological characteristics within tissues or cells, in situ detection using biosensor technology offers crucial insights into the nature, stage, and progression of diseases, paving the way for enhanced precision in diagnostic approaches and treatment strategies. The implementation of needle-shaped biosensors (N-biosensors) presents a highly promising method for conducting in situ measurements of clinical biomarkers in various organs, such as in the brain or spinal cord. Previous studies have highlighted the excellent performance of different N-biosensor designs in detecting biomarkers from clinical samples in vitro. Recent preclinical in vivo studies have also shown significant progress in the clinical translation of N-biosensor technology for in situ biomarker detection, enabling highly accurate diagnoses for cancer, diabetes, and infectious diseases. This article begins with an overview of current state-of-the-art benchtop N-biosensor designs, discusses their preclinical applications for sensitive diagnoses, and concludes by exploring the challenges and potential avenues for next-generation N-biosensor technology. Full article
(This article belongs to the Special Issue Nano Biosensors and Their Applications for In Vivo/Vitro Diagnosis—2nd Edition)
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16 pages, 4440 KiB  
Article
High Stability and Low Power Nanometric Bio-Objects Trapping through Dielectric–Plasmonic Hybrid Nanobowtie
by Paola Colapietro, Giuseppe Brunetti, Annarita di Toma, Francesco Ferrara, Maria Serena Chiriacò and Caterina Ciminelli
Biosensors 2024, 14(8), 390; https://doi.org/10.3390/bios14080390 - 13 Aug 2024
Viewed by 1298
Abstract
Micro and nano-scale manipulation of living matter is crucial in biomedical applications for diagnostics and pharmaceuticals, facilitating disease study, drug assessment, and biomarker identification. Despite advancements, trapping biological nanoparticles remains challenging. Nanotweezer-based strategies, including dielectric and plasmonic configurations, show promise due to their [...] Read more.
Micro and nano-scale manipulation of living matter is crucial in biomedical applications for diagnostics and pharmaceuticals, facilitating disease study, drug assessment, and biomarker identification. Despite advancements, trapping biological nanoparticles remains challenging. Nanotweezer-based strategies, including dielectric and plasmonic configurations, show promise due to their efficiency and stability, minimizing damage without direct contact. Our study uniquely proposes an inverted hybrid dielectric–plasmonic nanobowtie designed to overcome the primary limitations of existing dielectric–plasmonic systems, such as high costs and manufacturing complexity. This novel configuration offers significant advantages for the stable and long-term trapping of biological objects, including strong energy confinement with reduced thermal effects. The metal’s efficient light reflection capability results in a significant increase in energy field confinement (EC) within the trapping site, achieving an enhancement of over 90% compared to the value obtained with the dielectric nanobowtie. Numerical simulations confirm the successful trapping of 100 nm viruses, demonstrating a trapping stability greater than 10 and a stiffness of 2.203 fN/nm. This configuration ensures optical forces of approximately 2.96 fN with an input power density of 10 mW/μm2 while preserving the temperature, chemical–biological properties, and shape of the biological sample. Full article
(This article belongs to the Special Issue Nanotechnology-Based Optical Sensors for Biomedical Applications)
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19 pages, 5501 KiB  
Article
Detecting Nanotopography Induced Changes in Cell Migration Directions Using Oxygen Sensors
by Muting Wang and Stella W. Pang
Biosensors 2024, 14(8), 389; https://doi.org/10.3390/bios14080389 - 12 Aug 2024
Viewed by 1517
Abstract
This study investigates the oxygen (O2) consumption of single cells during changes in their migration direction. This is the first integration of nanotopographies with an O2 biosensor in a platform, allowing the real-time monitoring of O2 consumption in cells [...] Read more.
This study investigates the oxygen (O2) consumption of single cells during changes in their migration direction. This is the first integration of nanotopographies with an O2 biosensor in a platform, allowing the real-time monitoring of O2 consumption in cells and the ability to distinguish cells migrating in the same direction from those migrating in the opposite direction. Advanced nanofabrication technologies were used to pattern nanoholes or nanopillars on grating ridges, and their effects were evaluated using fluorescence microscopy, cell migration assays, and O2 consumption analysis. The results revealed that cells on the nanopillars over grating ridges exhibited an enhanced migration motility and more frequent directional changes. Additionally, these cells showed an increased number of protrusions and filopodia with denser F-actin areas and an increased number of dotted F-actin structures around the nanopillars. Dynamic metabolic responses were also evident, as indicated by the fluorescence intensity peaks of platinum octaethylporphyrin ketone dye, reflecting an increased O2 consumption and higher mitochondria activities, due to the higher energy required in response to directional changes. The study emphasizes the complex interplay between O2 consumption and cell migration directional changes, providing insights into biomaterial science and regenerative medicine. It suggests innovative designs for biomaterials that guide cell migration and metabolism, advocating nanoengineered platforms to harness the intricate relationships between cells and their microenvironments for therapeutic applications. Full article
(This article belongs to the Special Issue Nanotechnology-Based Optical Sensors for Biomedical Applications)
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13 pages, 2753 KiB  
Article
Development and Application of Colloidal Gold Test Strips for the Rapid Detection of Canine Brucellosis
by Pengxiang Sun, Xinmei Yang, Jinyue Liu, Yanqing Bao, Jingjing Qi, Xiangan Han, Guanhui Liu, Shaohui Wang and Mingxing Tian
Biosensors 2024, 14(8), 388; https://doi.org/10.3390/bios14080388 - 10 Aug 2024
Cited by 1 | Viewed by 2063
Abstract
Brucellosis is a global problem, with the causative agent being the genus Brucella. B. canis can cause undulant fever in dogs, which is a zoonotic disease that can spread not only among dogs but also to humans. This poses a public health [...] Read more.
Brucellosis is a global problem, with the causative agent being the genus Brucella. B. canis can cause undulant fever in dogs, which is a zoonotic disease that can spread not only among dogs but also to humans. This poses a public health threat to society. In this study, a rapid and straightforward immune colloidal gold test strip was developed for the diagnosis of canine brucellosis through the detection of anti-LPS antibodies in serum samples. Rabbit anti-canine IgG conjugated with colloidal gold was employed as the colloidal gold-labeled antibody. The extracted high-purity R-LPS was employed as the capture antigen in the test line (T-line), while goat anti-rabbit IgG was utilized as the capture antibody in the control line (C-line). The colloidal gold strip exhibited high specificity in the detection of brucellosis, with no cross-reaction observed with the common clinical canine diseases caused by Canine coronavirus (CCV), Canine distemper virus (CDV), and Canine parvovirus (CPV). In comparison to the commercial iELISA kit, the sensitivity and specificity of the colloidal gold test strip were found to be 95.23% and 98.76%, respectively. The diagnostic coincidence rate was 98.47%. The findings of this study indicate that colloidal gold test strips may be employed as a straightforward, expeditious, sensitive, and specific diagnostic instrument for the identification of canine brucellosis, particularly in resource-limited regions. Full article
(This article belongs to the Section Biosensors and Healthcare)
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11 pages, 1624 KiB  
Article
Enhanced Electrochemical Sensing of Oxalic Acid Based on VS2 Nanoflower-Decorated Glassy Carbon Electrode Prepared by Hydrothermal Method
by Mengfan Wu, Zhuang Sun, Peizheng Shi, Ningbin Zhao, Kaiqiang Sun, Chen Ye, He Li, Nan Jiang, Li Fu, Yunlong Zhou and Cheng-Te Lin
Biosensors 2024, 14(8), 387; https://doi.org/10.3390/bios14080387 - 9 Aug 2024
Cited by 1 | Viewed by 1530
Abstract
Oxalic acid (OA) is a predominant constituent in kidney stones, contributing to 70–80% of all cases. Rapid detection of OA is vital for the early diagnosis and treatment of kidney stone conditions. This work introduces a novel electrochemical sensing approach for OA, leveraging [...] Read more.
Oxalic acid (OA) is a predominant constituent in kidney stones, contributing to 70–80% of all cases. Rapid detection of OA is vital for the early diagnosis and treatment of kidney stone conditions. This work introduces a novel electrochemical sensing approach for OA, leveraging vanadium disulfide (VS2) nanoflowers synthesized via hydrothermal synthesis. These VS2 nanoflowers, known for their excellent electrocatalytic properties and large surface area, are used to modify glassy carbon electrodes for enhanced OA sensing. The proposed OA sensor exhibits high sensitivity and selectivity across a wide linear detection range of 0.2–20 μM, with an impressively low detection limit of 0.188 μM. The practicality of this sensor was validated through interference studies, offering a promising tool for the early diagnosis and monitoring of kidney stone diseases. Full article
(This article belongs to the Special Issue Advances, Challenges and Opportunities in the Use of 2D Materials for Biosensing and Biomedical Applications)
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10 pages, 4355 KiB  
Article
An Electrochemical Biosensor for the Detection of Pulmonary Embolism and Myocardial Infarction
by Yaw-Jen Chang, Fu-Yuan Siao and En-Yu Lin
Biosensors 2024, 14(8), 386; https://doi.org/10.3390/bios14080386 - 9 Aug 2024
Viewed by 4109
Abstract
Due to the clinical similarities between pulmonary embolism (PE) and myocardial infarction (MI), physicians often encounter challenges in promptly distinguishing between them, potentially missing the critical window for the correct emergency response. This paper presents a biosensor, termed the PEMI biosensor, which is [...] Read more.
Due to the clinical similarities between pulmonary embolism (PE) and myocardial infarction (MI), physicians often encounter challenges in promptly distinguishing between them, potentially missing the critical window for the correct emergency response. This paper presents a biosensor, termed the PEMI biosensor, which is designed for the identification and quantitative detection of pulmonary embolism or myocardial infarction. The surface of the working electrode of the PEMI biosensor was modified with graphene oxide and silk fibroin to immobilize the mixture of antibodies. Linear sweep voltammetry was employed to measure the current-to-potential mapping of analytes, with the calculated curvature serving as a judgment index. Experimental results showed that the curvature exhibited a linear correlation with the concentration of antigen FVIII, and a linear inverse correlation with the concentration of antigen cTnI. Given that FVIII and cTnI coexist in humans, the upper and lower limits were determined from the curvatures of a set of normal concentrations of FVIII and cTnI. An analyte with a curvature exceeding the upper limit can be identified as pulmonary embolism, while a curvature falling below the lower limit indicates myocardial infarction. Additionally, the further the curvature deviates from the upper or lower limits, the more severe the condition. The PEMI biosensor can serve as an effective detection platform for physicians. Full article
(This article belongs to the Section Biosensors and Healthcare)
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11 pages, 7955 KiB  
Article
Grating Bio-Microelectromechanical Platform Architecture for Multiple Biomarker Detection
by Fahimeh Marvi, Kian Jafari and Mohamad Sawan
Biosensors 2024, 14(8), 385; https://doi.org/10.3390/bios14080385 - 9 Aug 2024
Cited by 1 | Viewed by 1805
Abstract
A label-free biosensor based on a tunable MEMS metamaterial structure is proposed in this paper. The adopted structure is a one-dimensional array of metamaterial gratings with movable and fixed fingers. The moving unit of the optical detection system is a component of the [...] Read more.
A label-free biosensor based on a tunable MEMS metamaterial structure is proposed in this paper. The adopted structure is a one-dimensional array of metamaterial gratings with movable and fixed fingers. The moving unit of the optical detection system is a component of the MEMS structure, driven by the surface stress effect. Thus, these suspended optical nanoribbons can be moved and change the grating pattern by the biological bonds that happened on the modified cantilever surface. Such structural variations lead to significant changes in the optical response of the metamaterial system under illuminating angled light and subsequently shift its resonance wavelength spectrum. As a result, the proposed biosensor shows appropriate analytical characteristics, including the mechanical sensitivity of Sm = 11.55 μm/Nm−1, the optical sensitivity of So = Δλ/Δd = 0.7 translated to So = Δλ/Δσ = 8.08 μm/Nm−1, and the quality factor of Q = 102.7. Also, considering the importance of multi-biomarker detection, a specific design of the proposed topology has been introduced as an array for identifying different biomolecules. Based on the conducted modeling and analyses, the presented device poses the capability of detecting multiple biomarkers of disease at very low concentrations with proper precision in fluidic environments, offering a suitable bio-platform for lab-on-chip structures. Full article
(This article belongs to the Special Issue Micro-nano Optic-Based Biosensing Technology and Strategy)
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16 pages, 3834 KiB  
Article
A Device-on-Chip Solution for Real-Time Diffuse Correlation Spectroscopy Using FPGA
by Christopher H. Moore, Ulas Sunar and Wei Lin
Biosensors 2024, 14(8), 384; https://doi.org/10.3390/bios14080384 - 8 Aug 2024
Cited by 2 | Viewed by 1564
Abstract
Diffuse correlation spectroscopy (DCS) is a non-invasive technology for the evaluation of blood perfusion in deep tissue. However, it requires high computational resources for data analysis, which poses challenges in its implementation for real-time applications. To address the unmet need, we developed a [...] Read more.
Diffuse correlation spectroscopy (DCS) is a non-invasive technology for the evaluation of blood perfusion in deep tissue. However, it requires high computational resources for data analysis, which poses challenges in its implementation for real-time applications. To address the unmet need, we developed a novel device-on-chip solution that fully integrates all the necessary computational components needed for DCS. It takes the output of a photon detector and determines the blood flow index (BFI). It is implemented on a field-programmable gate array (FPGA) chip including a multi-tau correlator for the calculation of the temporal light intensity autocorrelation function and a DCS analyzer to perform the curve fitting operation that derives the BFI at a rate of 6000 BFIs/s. The FPGA DCS system was evaluated against a lab-standard DCS system for both phantom and cuff ischemia studies. The results indicate that the autocorrelation of the light correlation and BFI from both the FPGA DCS and the reference DCS matched well. Furthermore, the FPGA DCS system was able to achieve a measurement rate of 50 Hz and resolve pulsatile blood flow. This can significantly lower the cost and footprint of the computational components of DCS and pave the way for portable, real-time DCS systems. Full article
(This article belongs to the Special Issue Advances in Biosensors Based on Reflectometry)
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22 pages, 8826 KiB  
Article
Microbead-Encapsulated Luminescent Bioreporter Screening of P. aeruginosa via Its Secreted Quorum-Sensing Molecules
by Abraham Abbey Paul, Yael Schlichter Kadosh, Ariel Kushmaro and Robert S. Marks
Biosensors 2024, 14(8), 383; https://doi.org/10.3390/bios14080383 - 8 Aug 2024
Cited by 1 | Viewed by 2321
Abstract
Pseudomonas aeruginosa is an opportunistic Gram-negative bacterium that remains a prevalent clinical and environmental challenge. Quorum-sensing (QS) molecules are effective biomarkers in pinpointing the presence of P. aeruginosa. This study aimed to develop a convenient-to-use, whole-cell biosensor using P. aeruginosa reporters individually [...] Read more.
Pseudomonas aeruginosa is an opportunistic Gram-negative bacterium that remains a prevalent clinical and environmental challenge. Quorum-sensing (QS) molecules are effective biomarkers in pinpointing the presence of P. aeruginosa. This study aimed to develop a convenient-to-use, whole-cell biosensor using P. aeruginosa reporters individually encapsulated within alginate-poly-L-lysine (alginate-PLL) microbeads to specifically detect the presence of bacterial autoinducers. The PLL-reinforced microbeads were prepared using a two-step method involving ionic cross-linking and subsequent coating with thin layers of PLL. The alginate-PLL beads showed good stability in the presence of a known cation scavenger (sodium citrate), which typically limits the widespread applications of calcium alginate. In media containing synthetic autoinducers—such as N-(3-oxo dodecanoyl) homoserine lactone (3-oxo-C12-HSL) and N-butanoyl-L-homoserine lactone (C4-HSL), or the cell-free supernatants of planktonic or the flow-cell biofilm effluent of wild P. aeruginosa (PAO1)—the encapsulated bacteria enabled a dose-dependent detection of the presence of these QS molecules. The prepared bioreporter beads remained stable during prolonged storage at 4 and −80 °C and were ready for on-the-spot sensing without the need for recovery. The proof-of-concept, optical fiber-based, and whole-cell biosensor developed here demonstrates the practicality of the encapsulated bioreporter for bacterial detection based on specific QS molecules. Full article
(This article belongs to the Special Issue Prof. Shishmon Belkin 30th Anniversary of Working in Bioluminescent Bioreporter Bacteria Biosensors)
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13 pages, 1918 KiB  
Article
Electrical Conductivity Measurement in Human Liver Tissue: Assessment on Normal vs. Tumor Tissue and under In Vivo vs. Ex Vivo Conditions
by Amirhossein Sarreshtehdari, Tomás García-Sánchez, Patricia Sánchez-Velázquez, Benedetto Ielpo, Enrique Berjano, María Villamonte, Xavier Moll and Fernando Burdio
Biosensors 2024, 14(8), 382; https://doi.org/10.3390/bios14080382 - 8 Aug 2024
Viewed by 1892
Abstract
Background: This study evaluated electrical conductivity in human liver tissue in the 3–1000 kHz frequency range to compare normal versus tumor tissues under in vivo versus ex vivo conditions. Methods: Previous informed consent was obtained from twenty patients undergoing liver resection in whom [...] Read more.
Background: This study evaluated electrical conductivity in human liver tissue in the 3–1000 kHz frequency range to compare normal versus tumor tissues under in vivo versus ex vivo conditions. Methods: Previous informed consent was obtained from twenty patients undergoing liver resection in whom liver electrical conductivity was measured during surgery and after resection. Result: We found higher electrical conductivity values in tumor tissues than in normal tissue in both in vivo (0.41 ± 0.10 vs. 0.13 ± 0.06 S/m) and ex vivo (0.27 ± 0.09 vs. 0.12 ± 0.07 S/m) conditions (at 3 kHz). The electric properties also showed a promising potential for distinguishing between different tissue types including metastasis, cholangiocarcinoma (CCA), hepatocellular carcinoma (HCC), hepatic cirrhosis, and normal liver (both in vivo and ex vivo). At 3 kHz, in vivo electrical conductivity for cholangiocarcinoma, HCC, and metastasis were 0.35, 0.42 ± 0.13, and 0.41 ± 0.08 S/m, respectively, which differed significantly from each other (p < 0.05). Conclusions: These findings could potentially improve liver disease diagnostics through electrical conductivity measurements and treatment techniques involving electric fields. Future research should focus on expanding the sample size to refine the categorization and comparison processes across diverse human liver tissue types. Full article
(This article belongs to the Section Biosensor and Bioelectronic Devices)
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10 pages, 1894 KiB  
Communication
A Fluorescent Lateral Flow Immunoassay for the Detection of Skeletal Muscle Troponin I in Serum for Muscle Injury Monitoring at the Point of Care
by Deding Tang, Shuang Wu, Mengqi Kong, Zhaonan Liu, Zonghao Li, Ying Han, Yan Gong and Jie Hu
Biosensors 2024, 14(8), 381; https://doi.org/10.3390/bios14080381 - 8 Aug 2024
Viewed by 1589
Abstract
Exercise-induced muscle injury is one of the most common types of sports injuries. Skeletal muscle troponin I (skTnI) serves as an ideal biomarker in assessing such injuries, facilitating timely detection and evaluation. In this study, we develop a fluorescent sandwich lateral flow immunoassay [...] Read more.
Exercise-induced muscle injury is one of the most common types of sports injuries. Skeletal muscle troponin I (skTnI) serves as an ideal biomarker in assessing such injuries, facilitating timely detection and evaluation. In this study, we develop a fluorescent sandwich lateral flow immunoassay (LFIA) combined with a desktop analyzer for rapid detection of skTnI. Through optimizing the reaction system, the assay achieves a satisfying detection performance, reaching a limit of detection (LOD) of 0.5 ng/mL with a turnaround time of 15 min. The proposed detection platform offers portability, ease of use, and high sensitivity, which facilitates the monitoring of exercise-induced muscle injuries at the point of care. This feature is particularly advantageous for end users, enabling timely detection of sports-related injuries and ultimately enhancing prognosis and sports life. Full article
(This article belongs to the Special Issue Biosensing for Point-of-Care Diagnostics)
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14 pages, 7092 KiB  
Article
Dynamic Monitoring of Time-Dependent Evolution of Biomolecules Using Quantum Dots-Based Biosensors Assemblies
by Razvan Bocu
Biosensors 2024, 14(8), 380; https://doi.org/10.3390/bios14080380 - 7 Aug 2024
Viewed by 1551
Abstract
The dynamic monitoring of biomolecules that are part of cell membranes generally constitutes a challenge. Electrochemiluminescence (ECL) biosensor assemblies provide clear advantages concerning microscopic imaging. Therefore, this paper proposes and analyzes a quantum dots-based biosensor assembly. Thus, particular attention is granted to biomolecules [...] Read more.
The dynamic monitoring of biomolecules that are part of cell membranes generally constitutes a challenge. Electrochemiluminescence (ECL) biosensor assemblies provide clear advantages concerning microscopic imaging. Therefore, this paper proposes and analyzes a quantum dots-based biosensor assembly. Thus, particular attention is granted to biomolecules that are part of cell membranes. Additionally, this paper describes and analyzes a quantum dots-based biosensor assembly, which is used to implement a fully functional color ECL visualization system that allows for cellular and biomolecular structures to be accurately visualized. The related nano-emitter allows the implementation of real-time bioimaging scenarios. Consequently, the proposed approach is thoroughly evaluated relative to the time-dependent evolution of biomolecules. It has been demonstrated that traditionally problematic structures, like the biomolecules that are part of cell membranes, can be studied and monitored relative to their time-dependent dynamic evolution using the proposed solution. The reported research process has been conducted in the realm of cooperation with a specialized biomedical engineering company, and the described results are expected to substantially support a better understanding of the biomolecules’ time-dependent dynamic evolution. Full article
(This article belongs to the Special Issue Micro-nano Optic-Based Biosensing Technology and Strategy)
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14 pages, 4361 KiB  
Article
Implementation of Rapid Nucleic Acid Amplification Based on the Super Large Thermoelectric Cooler Rapid Temperature Rise and Fall Heating Module
by Jianxin Cheng, Enjia Zhang, Rui Sun, Kaihuan Zhang, Fangzhou Zhang, Jianlong Zhao, Shilun Feng and Bo Liu
Biosensors 2024, 14(8), 379; https://doi.org/10.3390/bios14080379 - 6 Aug 2024
Cited by 2 | Viewed by 1743
Abstract
In the rapid development of molecular biology, nucleic acid amplification detection technology has received more and more attention. The traditional polymerase chain reaction (PCR) instrument has poor refrigeration performance during its transition from a high temperature to a low temperature in the temperature [...] Read more.
In the rapid development of molecular biology, nucleic acid amplification detection technology has received more and more attention. The traditional polymerase chain reaction (PCR) instrument has poor refrigeration performance during its transition from a high temperature to a low temperature in the temperature cycle, resulting in a longer PCR amplification cycle. Peltier element equipped with both heating and cooling functions was used, while the robust adaptive fuzzy proportional integral derivative (PID) algorithm was also utilized as the fundamental temperature control mechanism. The heating and cooling functions were switched through the state machine mode, and the PCR temperature control module was designed to achieve rapid temperature change. Cycle temperature test results showed that the fuzzy PID control algorithm was used to accurately control the temperature and achieve rapid temperature rise and fall (average rising speed = 11 °C/s, average falling speed = 8 °C/s) while preventing temperature overcharging, maintaining temperature stability, and achieving ultra-fast PCR amplification processes (45 temperature cycle time < 19 min). The quantitative results show that different amounts of fluorescence signals can be observed according to the different concentrations of added viral particles, and an analytical detection limit (LoD) as low as 10 copies per μL can be achieved with no false positive in the negative control. The results show that the TEC amplification of nucleic acid has a high detection rate, sensitivity, and stability. This study intended to solve the problem where the existing thermal cycle temperature control technology finds it difficult to meet various new development requirements, such as the rapid, efficient, and miniaturization of PCR. Full article
(This article belongs to the Special Issue Biochips and Biosensors for Health-Care and Diagnostics)
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13 pages, 1815 KiB  
Article
Quantifying Plant Signaling Pathways by Integrating Luminescence-Based Biosensors and Mathematical Modeling
by Shakeel Ahmed, Syed Muhammad Zaigham Abbas Naqvi, Fida Hussain, Muhammad Awais, Yongzhe Ren, Junfeng Wu, Hao Zhang, Yiheng Zang and Jiandong Hu
Biosensors 2024, 14(8), 378; https://doi.org/10.3390/bios14080378 - 5 Aug 2024
Viewed by 1702
Abstract
Plants have evolved intricate signaling pathways, which operate as networks governed by feedback to deal with stressors. Nevertheless, the sophisticated molecular mechanisms underlying these routes still need to be comprehended, and experimental validation poses significant challenges and expenses. Consequently, computational hypothesis evaluation gains [...] Read more.
Plants have evolved intricate signaling pathways, which operate as networks governed by feedback to deal with stressors. Nevertheless, the sophisticated molecular mechanisms underlying these routes still need to be comprehended, and experimental validation poses significant challenges and expenses. Consequently, computational hypothesis evaluation gains prominence in understanding plant signaling dynamics. Biosensors are genetically modified to emit light when exposed to a particular hormone, such as abscisic acid (ABA), enabling quantification. We developed computational models to simulate the relationship between ABA concentrations and bioluminescent sensors utilizing the Hill equation and ordinary differential equations (ODEs), aiding better hypothesis development regarding plant signaling. Based on simulation results, the luminescence intensity was recorded for a concentration of 47.646 RLUs for 1.5 μmol, given the specified parameters and model assumptions. This method enhances our understanding of plant signaling pathways at the cellular level, offering significant benefits to the scientific community in a cost-effective manner. The alignment of these computational predictions with experimental results emphasizes the robustness of our approach, providing a cost-effective means to validate mathematical models empirically. The research intended to correlate the bioluminescence of biosensors with plant signaling and its mathematical models for quantified detection of specific plant hormone ABA. Full article
(This article belongs to the Section Optical and Photonic Biosensors)
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