Research

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19 pages, 4404 KiB

Open AccessArticle

Q3: A Compact Device for Quick, High Precision qPCR

by Marco Cereda, Alessandro Cocci, Davide Cucchi, Lillo Raia, Danilo Pirola, Lorenzo Bruno, Pietro Ferrari, Valentina Pavanati, Giorgia Calisti, Francesco Ferrara, Alessandro P. Bramanti and Marco A. Bianchessi

Sensors 2018, 18(8), 2583; https://doi.org/10.3390/s18082583 - 07 Aug 2018

Cited by 14 | Viewed by 4503

Abstract

An accurate and easy-to-use Q3 system for on-chip quantitative real-time Polymerase Chain Reaction (qPCR) is hereby demonstrated, and described in detail. The qPCR reactions take place inside a single-use Lab-on-a-Chip with multiple wells, each with 5 to 15 µL capacity. The same chip [...] Read more.

An accurate and easy-to-use Q3 system for on-chip quantitative real-time Polymerase Chain Reaction (qPCR) is hereby demonstrated, and described in detail. The qPCR reactions take place inside a single-use Lab-on-a-Chip with multiple wells, each with 5 to 15 µL capacity. The same chip hosts a printed metal heater coupled with a calibrated sensor, for rapid and accurate temperature control inside the reaction mixture. The rest of the system is non-disposable and encased in a 7 × 14 × 8.5 (height) cm plastic shell weighing 300 g. Included in the non-disposable part is a fluorescence read-out system featuring up to four channels and a self-contained control and data storage system, interfacing with an external user-friendly software suite. Hereby, we illustrate the engineering details of the Q3 system and benchmark it with seamlessly ported testing protocols, showing that Q3 equals the performance of standard commercial systems. Overall, to the best of our knowledge, this is one of the most mature general-purpose systems for on-chip qPCR currently available. Full article

(This article belongs to the Special Issue Lab-on-a-Chip–From Point of Care to Precision Medicine)

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13 pages, 1945 KiB

Open AccessArticle

Thermal Analysis of a Disposable, Instrument-Free DNA Amplification Lab-on-a-Chip Platform

by Tamás Pardy, Toomas Rang and Indrek Tulp

Sensors 2018, 18(6), 1812; https://doi.org/10.3390/s18061812 - 04 Jun 2018

Cited by 7 | Viewed by 4076

Abstract

Novel second-generation rapid diagnostics based on nucleic acid amplification tests (NAAT) offer performance metrics on par with clinical laboratories in detecting infectious diseases at the point of care. The diagnostic assay is typically performed within a Lab-on-a-Chip (LoC) component with integrated temperature regulation. [...] Read more.

Novel second-generation rapid diagnostics based on nucleic acid amplification tests (NAAT) offer performance metrics on par with clinical laboratories in detecting infectious diseases at the point of care. The diagnostic assay is typically performed within a Lab-on-a-Chip (LoC) component with integrated temperature regulation. However, constraints on device dimensions, cost and power supply inherent with the device format apply to temperature regulation as well. Thermal analysis on simplified thermal models for the device can help overcome these barriers by speeding up thermal optimization. In this work, we perform experimental thermal analysis on the simplified thermal model for our instrument-free, single-use LoC NAAT platform. The system is evaluated further by finite element modelling. Steady-state as well as transient thermal analysis are performed to evaluate the performance of a self-regulating polymer resin heating element in the proposed device geometry. Reaction volumes in the target temperature range of the amplification reaction are estimated in the simulated model to assess compliance with assay requirements. Using the proposed methodology, we demonstrated our NAAT device concept capable of performing loop-mediated isothermal amplification in the 20–25 °C ambient temperature range with 32 min total assay time. Full article

(This article belongs to the Special Issue Lab-on-a-Chip–From Point of Care to Precision Medicine)

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11 pages, 2318 KiB

Open AccessArticle

Integrated Optical Mach-Zehnder Interferometer Based on Organic-Inorganic Hybrids for Photonics-on-a-Chip Biosensing Applications

by Ana R. Bastos, Carlos M. S. Vicente, Rui Oliveira-Silva, Nuno J. O. Silva, Marta Tacão, João P. da Costa, Mário Lima, Paulo S. André and Rute A. S. Ferreira

Sensors 2018, 18(3), 840; https://doi.org/10.3390/s18030840 - 12 Mar 2018

Cited by 24 | Viewed by 7058

Abstract

The development of portable low-cost integrated optics-based biosensors for photonics-on-a-chip devices for real-time diagnosis are of great interest, offering significant advantages over current analytical methods. We report the fabrication and characterization of an optical sensor based on a Mach-Zehnder interferometer to monitor the [...] Read more.

The development of portable low-cost integrated optics-based biosensors for photonics-on-a-chip devices for real-time diagnosis are of great interest, offering significant advantages over current analytical methods. We report the fabrication and characterization of an optical sensor based on a Mach-Zehnder interferometer to monitor the growing concentration of bacteria in a liquid medium. The device pattern was imprinted on transparent self-patternable organic-inorganic di-ureasil hybrid films by direct UV-laser, reducing the complexity and cost production compared with lithographic techniques or three-dimensional (3D) patterning using femtosecond lasers. The sensor performance was evaluated using, as an illustrative example, E. coli cell growth in an aqueous medium. The measured sensitivity (2 × 10⁻⁴ RIU) and limit of detection (LOD = 2 × 10⁻⁴) are among the best values known for low-refractive index contrast sensors. Furthermore, the di-ureasil hybrid used to produce this biosensor has additional advantages, such as mechanical flexibility, thermal stability, and low insertion losses due to fiber-device refractive index mismatch (~1.49). Therefore, the proposed sensor constitutes a direct, compact, fast, and cost-effective solution for monitoring the concentration of lived-cells. Full article

(This article belongs to the Special Issue Lab-on-a-Chip–From Point of Care to Precision Medicine)

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12 pages, 3483 KiB

Open AccessArticle

Lab-on-a-Disc Platform for Automated Chemical Cell Lysis

by Moo-Jung Seo and Jae-Chern Yoo

Sensors 2018, 18(3), 687; https://doi.org/10.3390/s18030687 - 26 Feb 2018

Cited by 11 | Viewed by 5325

Abstract

Chemical cell lysis is an interesting topic in the research to Lab-on-a-Disc (LOD) platforms on account of its perfect compatibility with the centrifugal spin column format. However, standard procedures followed in chemical cell lysis require sophisticated non-contact temperature control as well as the [...] Read more.

Chemical cell lysis is an interesting topic in the research to Lab-on-a-Disc (LOD) platforms on account of its perfect compatibility with the centrifugal spin column format. However, standard procedures followed in chemical cell lysis require sophisticated non-contact temperature control as well as the use of pressure resistant valves. These requirements pose a significant challenge thereby making the automation of chemical cell lysis on an LOD extremely difficult to achieve. In this study, an LOD capable of performing fully automated chemical cell lysis is proposed, where a combination of chemical and thermal methods has been used. It comprises a sample inlet, phase change material sheet (PCMS)-based temperature sensor, heating chamber, and pressure resistant valves. The PCMS melts and solidifies at a certain temperature and thus is capable of indicating whether the heating chamber has reached a specific temperature. Compared to conventional cell lysis systems, the proposed system offers advantages of reduced manual labor and a compact structure that can be readily integrated onto an LOD. Experiments using Salmonella typhimurium strains were conducted to confirm the performance of the proposed cell lysis system. The experimental results demonstrate that the proposed system has great potential in realizing chemical cell lysis on an LOD whilst achieving higher throughput in terms of purity and yield of DNA thereby providing a good alternative to conventional cell lysis systems. Full article

(This article belongs to the Special Issue Lab-on-a-Chip–From Point of Care to Precision Medicine)

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12 pages, 2138 KiB

Open AccessArticle

Visual Estimation of Bacterial Growth Level in Microfluidic Culture Systems

by Kyukwang Kim, Seunggyu Kim and Jessie S. Jeon

Sensors 2018, 18(2), 447; https://doi.org/10.3390/s18020447 - 03 Feb 2018

Cited by 23 | Viewed by 8172

Abstract

Microfluidic devices are an emerging platform for a variety of experiments involving bacterial cell culture, and has advantages including cost and convenience. One inevitable step during bacterial cell culture is the measurement of cell concentration in the channel. The optical density measurement technique [...] Read more.

Microfluidic devices are an emerging platform for a variety of experiments involving bacterial cell culture, and has advantages including cost and convenience. One inevitable step during bacterial cell culture is the measurement of cell concentration in the channel. The optical density measurement technique is generally used for bacterial growth estimation, but it is not applicable to microfluidic devices due to the small sample volumes in microfluidics. Alternately, cell counting or colony-forming unit methods may be applied, but these do not work in situ; nor do these methods show measurement results immediately. To this end, we present a new vision-based method to estimate the growth level of the bacteria in microfluidic channels. We use Fast Fourier transform (FFT) to detect the frequency level change of the microscopic image, focusing on the fact that the microscopic image becomes rough as the number of cells in the field of view increases, adding high frequencies to the spectrum of the image. Two types of microfluidic devices are used to culture bacteria in liquid and agar gel medium, and time-lapsed images are captured. The images obtained are analyzed using FFT, resulting in an increase in high-frequency noise proportional to the time passed. Furthermore, we apply the developed method in the microfluidic antibiotics susceptibility test by recognizing the regional concentration change of the bacteria that are cultured in the antibiotics gradient. Finally, a deep learning-based data regression is performed on the data obtained by the proposed vision-based method for robust reporting of data. Full article

(This article belongs to the Special Issue Lab-on-a-Chip–From Point of Care to Precision Medicine)

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Review

Jump to: Research

34 pages, 9531 KiB

Open AccessReview

Key Enabling Technologies for Point-of-Care Diagnostics

by Elisabetta Primiceri, Maria Serena Chiriacò, Francesca M. Notarangelo, Antonio Crocamo, Diego Ardissino, Marco Cereda, Alessandro P. Bramanti, Marco A. Bianchessi, Gianluigi Giannelli and Giuseppe Maruccio

Sensors 2018, 18(11), 3607; https://doi.org/10.3390/s18113607 - 24 Oct 2018

Cited by 61 | Viewed by 6924

Abstract

A major trend in biomedical engineering is the development of reliable, self-contained point-of-care (POC) devices for diagnostics and in-field assays. The new generation of such platforms increasingly addresses the clinical and environmental needs. Moreover, they are becoming more and more integrated with everyday [...] Read more.

A major trend in biomedical engineering is the development of reliable, self-contained point-of-care (POC) devices for diagnostics and in-field assays. The new generation of such platforms increasingly addresses the clinical and environmental needs. Moreover, they are becoming more and more integrated with everyday objects, such as smartphones, and their spread among unskilled common people, has the power to improve the quality of life, both in the developed world and in low-resource settings. The future success of these tools will depend on the integration of the relevant key enabling technologies on an industrial scale (microfluidics with microelectronics, highly sensitive detection methods and low-cost materials for easy-to-use tools). Here, recent advances and perspectives will be reviewed across the large spectrum of their applications. Full article

(This article belongs to the Special Issue Lab-on-a-Chip–From Point of Care to Precision Medicine)

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41 pages, 9813 KiB

Open AccessReview

Lab-on-Chip for Exosomes and Microvesicles Detection and Characterization

by Maria Serena Chiriacò, Monica Bianco, Annamaria Nigro, Elisabetta Primiceri, Francesco Ferrara, Alessandro Romano, Angelo Quattrini, Roberto Furlan, Valentina Arima and Giuseppe Maruccio

Sensors 2018, 18(10), 3175; https://doi.org/10.3390/s18103175 - 20 Sep 2018

Cited by 111 | Viewed by 11706

Abstract

Interest in extracellular vesicles and in particular microvesicles and exosomes, which are constitutively produced by cells, is on the rise for their huge potential as biomarkers in a high number of disorders and pathologies as they are considered as carriers of information among [...] Read more.

Interest in extracellular vesicles and in particular microvesicles and exosomes, which are constitutively produced by cells, is on the rise for their huge potential as biomarkers in a high number of disorders and pathologies as they are considered as carriers of information among cells, as well as being responsible for the spreading of diseases. Current methods of analysis of microvesicles and exosomes do not fulfill the requirements for their in-depth investigation and the complete exploitation of their diagnostic and prognostic value. Lab-on-chip methods have the potential and capabilities to bridge this gap and the technology is mature enough to provide all the necessary steps for a completely automated analysis of extracellular vesicles in body fluids. In this paper we provide an overview of the biological role of extracellular vesicles, standard biochemical methods of analysis and their limits, and a survey of lab-on-chip methods that are able to meet the needs of a deeper exploitation of these biological entities to drive their use in common clinical practice. Full article

(This article belongs to the Special Issue Lab-on-a-Chip–From Point of Care to Precision Medicine)

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23 pages, 27810 KiB

Open AccessReview

A Review of Planar PIV Systems and Image Processing Tools for Lab-On-Chip Microfluidics

by Fahrettin Gökhan Ergin, Bo Beltoft Watz and Nicolai Fog Gade-Nielsen

Sensors 2018, 18(9), 3090; https://doi.org/10.3390/s18093090 - 13 Sep 2018

Cited by 17 | Viewed by 8064

Abstract

Image-based sensor systems are quite popular in micro-scale flow investigations due to their flexibility and scalability. The aim of this manuscript is to provide an overview of current technical possibilities for Particle Image Velocimetry (PIV) systems and related image processing tools used in [...] Read more.

Image-based sensor systems are quite popular in micro-scale flow investigations due to their flexibility and scalability. The aim of this manuscript is to provide an overview of current technical possibilities for Particle Image Velocimetry (PIV) systems and related image processing tools used in microfluidics applications. In general, the PIV systems and related image processing tools can be used in a myriad of applications, including (but not limited to): Mixing of chemicals, droplet formation, drug delivery, cell counting, cell sorting, cell locomotion, object detection, and object tracking. The intention is to provide some application examples to demonstrate the use of image processing solutions to overcome certain challenges encountered in microfluidics. These solutions are often in the form of image pre- and post-processing techniques, and how to use these will be described briefly in order to extract the relevant information from the raw images. In particular, three main application areas are covered: Micro mixing, droplet formation, and flow around microscopic objects. For each application, a flow field investigation is performed using Micro-Particle Image Velocimetry (µPIV). Both two-component (2C) and three-component (3C) µPIV systems are used to generate the reported results, and a brief description of these systems are included. The results include detailed velocity, concentration and interface measurements for micromixers, phase-separated velocity measurements for the micro-droplet generator, and time-resolved (TR) position, velocity and flow fields around swimming objects. Recommendations on, which technique is more suitable in a given situation are also provided. Full article

(This article belongs to the Special Issue Lab-on-a-Chip–From Point of Care to Precision Medicine)

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