Search Results (127)

The detection of aliphatic and aromatic biogenic amines (BAs) is important in food spoilage, environmental monitoring, and disease diagnosis and treatment. Existing fluorescent probes predominantly detect aliphatic BAs with single signal variation and low sensitivity, impairing the adaptability of discriminative sensing platforms. Herein, we present a visual chemosensor (galactose-functionalized pyrrolopyrrole aza-BODIPY, PPAB-Gal) that simultaneously detects eight aliphatic and aromatic BAs in a real-time and intuitive way based on their unique electronic and structural features. Our findings reveal that the dual colorimetric and ratiometric emission changes are rapidly produced in presence of eight BAs through a noncovalent interaction (π–π stacking and hydrogen bond)-assisted chromophore reaction. Specifically, other lone-pair electrons containing compounds, such as secondary amines, tertiary amines, NH₃, and thiol, fail to exhibit these changes. As a result, superior sensing performances with distinctly dual signals (Δλ_ab = 130 nm, Δλ_em = 150 nm), a low LOD (~25 nM), and fast response time (<2 min) were obtained. Based on these advantages, a qualitative and smartphone-assisted sensing platform with a PPAB-Gal-loaded TLC plate is developed for visual detection of putrescine and cadaverine vapor. More importantly, we construct a connection between a standard quantitative index for the TVBN value and fluorescence signals to quantitatively determine the freshness of tuna and shrimp, and the method is facile and convenient for real-time and on-site detection in practical application. Furthermore, since the overexpressed spermine is an important biomarker of cancer diagnosis and treatment, PPAB-Gal NPs can be used to ratiometrically image spermine in living cells. This work provides a promising sensing method for BAs with a novel fluorescent material in food safety fields and biomedical assays. Full article

Heavy industry is a significant contributor to CO₂ global emissions, accounting for approximately 25% of the total. In Europe, the continent’s largest emitting industries, including steel, cement, and power generation, face significant decarbonization challenges due to multiple interrelated factors. Heavy industry must achieve carbon neutrality by 2050, as outlined in the 13th United Nations Sustainable Goals. One strategy to achieve this goal involves Carbon Capture Utilization and Storage (CCUS) with post-combustion carbon capture (PCC) technologies playing a critical role. Key methods include absorption, which uses chemical solvents like amines; adsorption, employing solid sorbents; cyclic CO₂ capture, such as calcium looping methods; cryogenic separation, which involves chilling flue gas to liquefy CO₂; and membrane separation, leveraging polymeric materials. Each technology offers unique advantages and challenges, necessitating hybrid approaches and policy support for widespread adoption. In this sense, this review provides a comprehensive overview of the existing European pilot and demonstration units and projects, funded by the EU across several industries. It specifically focuses on PCC. This study examines 111 industrial facilities across Europe, documenting the PCC technologies deployed at plants of varying capacities, geographic locations, and operational stakeholders. The review further evaluates the techno-economic performance of these systems, assessing their potential to advance carbon neutrality in heavy industries. Full article

Background/Objectives: G protein-coupled trace amine-associated receptors (TAARs) belong to a family of biogenic amine-sensing receptors. TAAR1 is the best-investigated receptor of this family, and TAAR1 agonists are already being tested in clinical studies for the treatment of schizophrenia, anxiety, and depression. Meanwhile, other TAARs (TAAR2, TAAR5, TAAR6, TAAR8, and TAAR9 in humans) are mostly known for their olfactory function, sensing innate odors. At the same time, there is growing evidence that these receptors may also be involved in brain function. TAAR8 is the least studied TAAR family member, and currently, there is no data on its function in the mammalian central nervous system. Methods: We generated triple knockout (tTAAR8-KO) mice lacking all murine Taar8 isoforms (Taar8a, Taar8b, and Taar8c) using CRISPR-Cas9 technology. In this study, we performed the first phenotyping of tTAAR8-KO mice for behavioral, electrophysiological, and neurochemical characteristics. Results: During the study, we found a number of alterations specific to tTAAR8-KO mice compared to controls. tTAAR8-KO mice demonstrated better short-term memory, more depressive-like behavior, and higher body temperature. Also, we observed changes in the dopaminergic system, brain electrophysiological activity, and adult neurogenic functions in mice lacking Taar8 isoforms. Conclusions: Based on the data obtained, it can be assumed that the physiological TAAR8 role is not limited only to the innate olfactory function, as previously proposed. TAAR8 could be involved in brain function, in particular in dopamine function regulation. Full article

A nanostructured sensing platform was developed by integrating gold-decorated lignin nanoparticles (AuLNPs) into electrospun polylactic acid (PLA) fibre mats. The composite material combines the high surface-to-volume ratio of PLA nanofibres with the chemical functionality of lignin—a polyphenolic biopolymer rich in hydroxyl and aromatic groups—enabling selective interactions with volatile amines through hydrogen bonding and Van der Waals forces. The embedded gold nanoparticles (AuNPs) further enhance the sensor’s electrical conductivity and provide catalytic sites for improved analyte interaction. The sensor exhibited selective adsorption of amine vapours, showing particularly strong affinity for dimethylamine (DMA), with a limit of detection (LOD) of approximately 440 ppb. Relative humidity (RH) was found to significantly influence sensor performance by facilitating amine protonation, thus promoting interaction with the sensing surface. The developed sensor demonstrated excellent selectivity, sensitivity and reproducibility, highlighting its potential for real-time detection of amines in environmental monitoring, industrial safety and healthcare diagnostics. Full article

Nitrogen and sulfur-co-doped carbon dots (N, S-CDs) were synthesized using a simple, eco-friendly hydrothermal technique with L-cysteine as the precursor. The synthesis approach produced highly water-dispersible, heteroatom-doped CDs with surface functional groups comprising amine, carboxyl, thiol, and sulfonic acid. Data analysis of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) confirmed their amorphous nature, nanoscale dimensions (1–8 nm, average particle size of 2.6 nm), and surface chemistry. Optical examination revealed intense and pure blue fluorescence emission under UV excitation, with excitation-dependent emission behavior attributed to surface defects and heteroatom doping. The N, S-CDs were applied as fluorescent probes for detecting perfluorooctanesulfonic acid (PFOS), a notable component of the perfluoroalkyl substances (PFAS) family, demonstrating pronounced and concentration-dependent fluorescence quenching. A linear detection range of 3.33–20 µM and a limit of detection (LOD) of 2 µM were reported using the N, S-CDs probe. UV-Vis spectral shifts and dye-interaction investigations indicated that the sensing mechanism is regulated by non-covalent interactions, primarily electrostatic and hydrophobic forces. These findings confirm the potential of N, S-CDs to be used as effective optical sensors for detecting PFOS in environmental monitoring applications. Full article

CO₂-responsive polymers have emerged as a significant class of smart materials, distinguished by their ability to reversibly alter their properties upon exposure to CO₂. Due to CO₂’s abundant availability, low cost, non-toxicity, energy efficiency, and excellent biocompatibility, these polymers offer remarkable environmental and practical advantages. This review succinctly explores recent advancements in the synthesis, mechanisms, and applications of CO₂-responsive polymers, emphasizing the pivotal roles of specific acidic and basic functional groups such as carboxylic acids, phenolic groups, amines, amidines, guanidines, and imidazoles. Advanced polymerization techniques including free radical polymerization (FRP), atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer (RAFT), and nitroxide-mediated polymerization (NMP) are critically evaluated for their precision and flexibility in polymer design. Significant applications in smart separation, carbon capture, drug delivery, desalination, emulsions, tissue engineering, and sensing technologies are discussed comprehensively. Although substantial progress has been made, ongoing challenges include enhancing response speed, durability, sustainability, and economic viability. Future research is recommended to focus on innovative polymer structures, computational modeling, hybrid materials, and greener synthesis methods. This review aims to inspire continued exploration and practical utilization of CO₂-responsive polymers to address pressing environmental and technological needs. Full article

Glucose (Glu) detection, as a fundamental analytical technique, has applications in medical diagnostics, clinical testing, bioanalysis and environmental monitoring. In this work, a solid-phase electrochemiluminescence (ECL) enzyme sensor was developed by immobilizing the ECL emitter in a stable manner within bipolar silica nanochannel array film (bp-SNA), enabling sensitive glucose detection. The sensor was constructed using an electrochemical-assisted self-assembly (EASA) method with various siloxane precursors to quickly modify the surface of indium tin oxide (ITO) electrodes with a bilayer SNA of different charge properties. The inner layer, including negatively charged SNA (n-SNA), attracted the positively charged ECL emitter tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)₃²⁺) via electrostatic interaction, while the outer layer, including positively charged SNA (p-SNA), repelled it, forming a barrier that efficiently concentrated the Ru(bpy)₃²⁺ emitter in a stable manner. After modifying the amine groups on the p-SNA surface with aldehyde groups, glucose oxidase (GOx) was covalently immobilized, forming the enzyme electrode. In the presence of glucose, GOx catalyzed the conversion of glucose to hydrogen peroxide (H₂O₂), which acted as a quencher for the Ru(bpy)₃²⁺/triethanolamine (TPA) system, reducing the ECL signal and enabling quantitative glucose analysis. The sensor exhibited a wide linear range from 10 μM to 7.0 mM and a limit of detection (LOD) of 1 μM (S/N = 3). Glucose detection in fetal bovine serum was realized. By replacing the enzyme type on the electrode surface, this sensing strategy holds the potential to provide a universal platform for the detection of different metabolites. Full article

Cellulose nanofibril (CNF) is a sort of novel nanomaterial directly extracted from plant resources, inheriting the advantages of cellulose as a cheap, green and renewable material for the development of new-generation eco-friendly electronics. In recent years, CNF-based triboelectric nanogenerator (TENG) has attracted increasing research interests, as the unique chemical, morphological, and electrical properties of CNF render the device with considerable flexibility, mechanical strength, and triboelectric output. In this study, we explore the use of isoreticular metal-organic frameworks (IRMOF) as functional filler to improve the performance of CNF based TENGs. Two types of IRMOFs that own the same network topology, namely IRMOF-1 and its aminated version IRMOF-3, are embedded with CNF to fabricated TENGs; their contribution to triboelectric output enhancement, including the roughness effect induced by large particles as well as the charge induction effect arisen from -NH₂ groups, are discussed. The performance-enhanced CNF-based TENG with 0.6 wt.% of IRMOF-3 is utilized to harvest mechanical energy from human activities and charge commercial capacitors, from which the electrical energy is sufficient to light up light-emitting diodes (LEDs) and drive low-power electronic devices. In addition, a locomotor analysis system is established by assembling the above TENGs and capacitors into a 3 × 3 sensing array, which allowed signal extraction from each sensing unit to display a motion distribution map. These results demonstrate the great potential of CNF/IRMOF-based TENGs for development of self-powered sensing devices for long-term motion monitoring. Full article

The controlled functionalization of graphene is critical for tuning and enhancing its properties, thereby expanding its potential applications. Covalent functionalization offers a deeper tuning of the geometric and electronic structure of graphene compared to non-covalent methods; however, the existing techniques involve side reactions and spatially uncontrolled functionalization, pushing research toward more selective and controlled methods. A promising approach is 1,3-dipolar cycloaddition, successfully utilized with carbon nanotubes. In the present work, this method has been extended to graphene flakes with low defect concentration. A key innovation is the use of a custom-synthesized ylide with a protected amine group (Boc), facilitating subsequent attachment of functional molecules. Indeed, after Boc cleavage, fluorescent dyes (Atto 425, 465, and 633) were covalently linked via NHS ester derivatization. This approach represents a highly selective method of minimizing structural damage. Successful functionalization was demonstrated by Raman spectroscopy, photoluminescence spectroscopy, and confocal microscopy, confirming the effectiveness of the method. This novel approach offers a versatile platform, enabling its use in biological imaging, sensing, and advanced nanodevices. The method paves the way for the development of sensors and devices capable of anchoring a wide range of molecules, including quantum dots and nanoparticles. Therefore, it represents a significant advancement in graphene-based technologies. Full article

Mammals, including humans, sense smell by the responses of odorant receptors (ORs) to odor molecules. We have developed an effective method to identify novel antagonists capable of suppressing the pungent odor of cat urine by targeting specific ORs. Since odors are typically complex mixtures of multiple volatile compounds, olfactory perception can vary depending on the composition. We analyzed the response of ORs to cat urine odor using vapor stimulation assays to identify the responding ORs. Gas chromatography–mass spectrometry was then performed to identify compounds eliciting responses from these ORs. Trace-amine-associated receptor 5 (TAAR5) demonstrated a significant response associated with the odor intensity of cat urine, identifying trimethylamine as a major contributor to the strong odor. From hundreds of candidate compounds, we identified several novel antagonists that exhibited greater efficacy than a known TAAR5 antagonist. These compounds not only reduced the responses of TAAR5-expressing cells to cat urine odor but also significantly reduced odor intensity and improved sensory pleasantness in human tests. Our findings suggest that targeting ORs responsive to specific odors, without isolating their individual components, is a promising strategy for developing deodorizing agents against complex malodors like cat urine odor. This study emphasizes the value of using real odor mixtures to enhance our understanding of odor perception. Full article

Deep eutectic solvents (DES) have emerged as versatile, sustainable media for the synthesis of nanomaterials due to their low toxicity, tunability, and biocompatibility. This study develops a one-step method to modify commercially available screen-printed electrodes (SPE) using laser-induced pyrolysis of DES, consisting of choline chloride and tartaric acid with dissolved nickel acetate and dispersed graphene. The electrodes were patterned using a 532 nm continuous-wave laser for the in situ formation of Ni nanoparticles decorated on graphene sheets directly on the SPE surface (Ni-G/SPE). The synthesis parameters, specifically laser power and graphene concentration, were optimized using the Nelder–Mead method to produce modified Ni-G/SPEs with maximized electrochemical response to dopamine. Electrochemical characterization of the developed sensor by differential pulse voltammetry revealed its broad linear detection range from 0.25 to 100 μM and high sensitivity with a low detection limit of 0.095 μM. These results highlight the potential of laser-assisted DES synthesis to advance electrochemical sensing technologies, particularly for the detection of biogenic amines. Full article

NO₂ is a toxic gas that can damage the lungs with prolonged exposure and contribute to health conditions, such as asthma in children. Detecting NO₂ is therefore crucial for maintaining a healthy environment. Carbon nanotubes (CNTs) are promising materials for NO₂ gas sensors due to their excellent electronic properties and high adsorption energy for NO₂ molecules. However, conventional CNT-based sensors face challenges, including low responses at room temperature (RT) and slow recovery times. This study introduces a memristor-based NO₂ gas sensor comprising CNT/ZnO/ITO decorated with an N-[3-(trimethoxysilyl)propyl] ethylene diamine (en-APTAS) membrane to enhance room-temperature-sensing performance. The amine groups in the en-APTAS membrane increase adsorption sites and boost charge transfer interactions between NO₂ and the CNT surface. This modification improves the sensor’s response by 60% at 20 ppm compared to the undecorated counterpart. However, the high adsorption energy of NO₂ slows the recovery process. To overcome this, a pulse-recovery method was implemented, applying a −2.5 V pulse with a 1 ms width, enabling the sensor to return to its baseline within 1 ms. These findings highlight the effectiveness of en-APTAS decoration and pulse-recovery techniques in improving the sensitivity, response, and recovery of CNT-based gas sensors. Full article

BF₃, volatile amines (VOAs), and biogenic amines (BAs) are the key indicators in chemical reaction catalysis and food quality monitoring. In this study, we present two types of fluorescent sensors, a hydrazone ligand (HL)-based fluorescent sensor for BF₃ detection and a novel sensor array using six boron difluoride (BF₂) hydrazone complexes (BFHs) for monitoring VOAs and BAs. Spectral research indicates that the interaction mechanism between the HLs and BF₃ is based on intramolecular charge transfer (ICT). The HLs for the monitoring of BF₃ showed good sensitivity, selectivity, and anti-interference and have the characteristics of a visible color change. Additionally, the HL probe demonstrates reversibility in the presence of triethylamine, making it a candidate for “ON-OFF-ON” mode sensing. BF₃ detection can also be efficiently performed using test strips for convenient, air-based applications. The BFH sensor array successfully differentiates histamine from the other typical non-volatile BAs in solution; in comparison, the VOAs are analyzed through recognition patterns and statistical analysis. The array’s color changes enable the practical, on-site detection of shrimp spoilage, with principal component analysis distinguishing various ageing intervals. In summary, this sensor array demonstrates high selectivity for VOAs and BAs, with significant potential for application in real-world sample analysis. Full article

Amine neurotransmitters (NTs) are crucial in the central nervous system, and dysregulation in their levels is implicated in a spectrum of neurological disorders. Thus, a precise and timely assessment of their concentrations is critical for early diagnosis and treatment efficacy monitoring. Graphene-based field effect transistors (GFETs) have become a ground-breaking instrument in the detection of these NTs because of their exceptional electrical characteristics and adaptability. This paper summarises the significant advancements in GFET biosensors in amine NT detection and highlights developments in the selectivity, sensitivity, and limit of detection (LOD) attained by selecting various graphene materials and functionalisation approaches. Full article

We are proposing a novel self-assembled monolayer (SAM) functionalized ZnO nanowires (NWs)-based conductometric sensor for the selective detection of hydrogen (H₂). The modulation of the surface electron density of ZnO NWs due to the presence of negatively charged terminal amine groups (−NH₂) of monolayers leads to an enhanced electron donation from H₂ to ZnO NWs. This, in turn, increases the relative change in the conductance (response) of functionalized ZnO NWs as compared to bare ones. In contrast, the sensing mechanism of bare ZnO NWs is determined by the chemisorbed oxygen ions. The functionalized ZnO NWs exhibit an eight times higher response compared to bare ZnO NWs at an optimal working temperature of 200 °C. Finally, in comparison to studies in the literature involving strategies to enhance the sensing performance of metal oxides toward H₂, like decoration with metal nanoparticles, heterostructures, and functionalization with a metal–organic framework, etc., SAM functionalization showed superior sensing results. Full article