On-chip quantitative detection of pathogen genes by autonomous microfluidic PCR platform

Multiple sensor electrodes, a supplementary electrode, a reference electrode, and signal-processing circuits were integrated on a single chip to develop a chip-shaped electrochemical sensing system. L-lactate and glucose were measured using on-chip working electrodes modified by polyion complex to immobilize lactate oxidase and glucose oxidase, respectively. Cyclic voltammetry measurements were conducted using an on-chip potentiostat. Selective and quantitative detection of glucose and L-lactate and the interference behavior were studied. Hydrogen peroxide generated by enzymatic reactions was detected by an increase in anodic oxidation current. Reaction currents at +0.7 V versus Ag/AgCl were used to obtain calibration plots. The measured dynamic ranges for L-lactate and glucose were 0.2–1.0 mM and 2.0–8.0 mM, respectively. The sensitivities were 65 nA/mM and 15 nA/mM, respectively, using a working electrode of 0.5 mm2. The 3σdetection limit was 0.19 mM and 1.1 mM, respectively. We have achieved multiple biomaterial detections on a circuit-equipped single chip. This integrated electrochemical sensor chip could be the best candidate for realizing point-of-care testing due to its portability and potential for mass production.

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Time Optimization of Heterogeneous Immunoassay Using PDMS Microfluidic Chip for Quantitative Detection of a Model Analyte

ASME 2008 6th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2008-62294 ◽

2008 ◽

Author(s):

Peng Li ◽

Assem Abolmaaty ◽

Thomas Barek ◽

Constantine Anagnostopoulos ◽

Mohammad Faghri

Keyword(s):

High Specificity ◽

Quantitative Detection ◽

Biomolecule Detection ◽

Diffusion Limited ◽

Time Optimization ◽

Single Process ◽

Heterogeneous Immunoassay ◽

On Chip ◽

Time Required ◽

Limited Process

Heterogeneous immunoassay (HI) has been recently used for on-chip biomolecule detection by many researchers due to its high specificity and precision. However, the protocols that have been published are too time-consuming. For HI based immunosensor to be attractive they should have short analysis times. In our work, a polydimethylsiloxane (PDMS) microfluidic device was fabricated to quantify a model analyte (bovine IgG) and used for optimizing the time required for each process. The results show that the incubation time of one single process could be reduced from typical 1 hour to 5 minutes without loss of performance. Our studies reveal that microfluidic devices are only effective in reducing incubation times for diffusion limited processes but not for interaction or adsorption limited process.

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Detector-Free Photothermal Bar-Chart Microfluidic Chips (PT-Chips) for Visual Quantitative Detection of Biomarkers

10.26434/chemrxiv.14131514 ◽

2021 ◽

Author(s):

Wan Zhou ◽

Guanglei Fu [email protected] ◽

Xiujun Li

Keyword(s):

Whole Blood ◽

Limit Of Detection ◽

Point Of Care ◽

Clinical Diagnostics ◽

Detection Sensitivity ◽

Quantitative Detection ◽

Microfluidic Chips ◽

Analytical Instruments ◽

Photothermal Effects ◽

On Chip

<p>The volumetric bar-chart microfluidic chips (V-Chips) driven by chemical reaction-generated gas provide a promising platform for point-of-care (POC) visual biomarker quantitation. However, multiple limitations are encountered in conventional V-Chips, such as costly and complex chip fabrication, complicated assembly, and imprecise controllability of gas production. Herein, we introduced nanomaterial-mediated photothermal effects to V-Chips, and for the first time developed a new type of V-Chip, <u>p</u>hoto<u>t</u>hermal bar-chart microfluidic <u>c</u>hip (PT-Chip), for visual quantitative detection of biochemicals without any bulky and costly analytical instruments. Immunosensing signals were converted to visual readout signals via photothermal effects, the on-chip bar-chart movements, enabling quantitative biomarker detection on a low-cost polymer hybrid PT-Chip with on-chip scale rulers. Four different human serum samples containing prostate-specific antigen (PSA) as a model analyte were detected simultaneously using the PT-Chip, with the limit of detection of 2.1 ng/mL, meeting clinical diagnostic requirements. Although no conventional signal detectors were used, it achieved comparable detection sensitivity to absorbance measurements with a microplate reader. The PT-Chip was further validated by testing human whole blood without the color interference problem, demonstrating good analytical performance of our method even in complex matrixes and thus the potential to fill a gap in current clinical diagnostics that is incapable of testing whole blood. This new PT-Chip driven by nanomaterial-mediated photothermal effects opens a new horizon of microfluidic platforms for instrument-free diagnostics at the point of care.</p>

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Detector-Free Photothermal Bar-Chart Microfluidic Chips (PT-Chips) for Visual Quantitative Detection of Biomarkers

10.26434/chemrxiv.14131514.v1 ◽

2021 ◽

Author(s):

Wan Zhou ◽

Guanglei Fu [email protected] ◽

Xiujun Li

Keyword(s):

Whole Blood ◽

Limit Of Detection ◽

Point Of Care ◽

Clinical Diagnostics ◽

Detection Sensitivity ◽

Quantitative Detection ◽

Microfluidic Chips ◽

Analytical Instruments ◽

Photothermal Effects ◽

On Chip

<p>The volumetric bar-chart microfluidic chips (V-Chips) driven by chemical reaction-generated gas provide a promising platform for point-of-care (POC) visual biomarker quantitation. However, multiple limitations are encountered in conventional V-Chips, such as costly and complex chip fabrication, complicated assembly, and imprecise controllability of gas production. Herein, we introduced nanomaterial-mediated photothermal effects to V-Chips, and for the first time developed a new type of V-Chip, <u>p</u>hoto<u>t</u>hermal bar-chart microfluidic <u>c</u>hip (PT-Chip), for visual quantitative detection of biochemicals without any bulky and costly analytical instruments. Immunosensing signals were converted to visual readout signals via photothermal effects, the on-chip bar-chart movements, enabling quantitative biomarker detection on a low-cost polymer hybrid PT-Chip with on-chip scale rulers. Four different human serum samples containing prostate-specific antigen (PSA) as a model analyte were detected simultaneously using the PT-Chip, with the limit of detection of 2.1 ng/mL, meeting clinical diagnostic requirements. Although no conventional signal detectors were used, it achieved comparable detection sensitivity to absorbance measurements with a microplate reader. The PT-Chip was further validated by testing human whole blood without the color interference problem, demonstrating good analytical performance of our method even in complex matrixes and thus the potential to fill a gap in current clinical diagnostics that is incapable of testing whole blood. This new PT-Chip driven by nanomaterial-mediated photothermal effects opens a new horizon of microfluidic platforms for instrument-free diagnostics at the point of care.</p>

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An integrated homogeneous SPARCL™ immunoassay for rapid biomarker detection on a chip

Analytical Methods ◽

10.1039/c9ay00198k ◽

2019 ◽

Vol 11 (19) ◽

pp. 2542-2550 ◽

Cited By ~ 2

Author(s):

Natalia Sandetskaya ◽

Nicole Isserstedt-John ◽

Andreas Kölsch ◽

Sebastian Schattschneider ◽

Dirk Kuhlmeier

Keyword(s):

Quantitative Detection ◽

Biomarker Detection ◽

On Chip ◽

Detection Of Biomarkers

A very simple and rapid homogeneous SPARCL™ immunoassay with on-chip preserved dry reagents enables sensitive quantitative detection of biomarkers.

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Integrated three-dimensional system-on-chip for direct quantitative detection of mitochondrial DNA mutation in affected cells

Biosensors and Bioelectronics ◽

10.1016/j.bios.2013.02.015 ◽

2013 ◽

Vol 48 ◽

pp. 6-11 ◽

Cited By ~ 4

Author(s):

Chen-Min Chang ◽

Li-Fang Chiu ◽

Yau-Huei Wei ◽

Dar-Bin Shieh ◽

Gwo-Bin Lee

Keyword(s):

Mitochondrial Dna ◽

Three Dimensional ◽

System On Chip ◽

Quantitative Detection ◽

Dimensional System ◽

Mitochondrial Dna Mutation ◽

Dna Mutation ◽

On Chip ◽

Three Dimensional System

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Real-Time Highly-Sensitive Protein Quantification Through On-Chip Chemiluminescence

10.26434/chemrxiv.12646376.v1 ◽

2020 ◽

Author(s):

Hoi Kei Chiu ◽

Tadas Kartanas ◽

Sean R. A. Devenish ◽

Kadi Saar ◽

Carina Mouritsen Luxhøj ◽

...

Keyword(s):

Background Noise ◽

Protein Quantification ◽

Quantitative Detection ◽

Background Signal ◽

Microfluidic Mixing ◽

Highly Sensitive ◽

Amine Groups ◽

On Chip ◽

Highly Sensitive Detection ◽

Illumination Source

<div> <div> <div> <p>A range of experimental methods have been developed to achieve highly sensitive detection and quantification of proteins. The majority of these methods rely on fluorescence-mediated readouts and, as such, their sensitivity can be affected by factors such as photobleaching of fluorophores and background signal from the illumination source. Both of these limitations can be overcome by using chemiluminescence-based detection: in contrast to fluorescence, chemiluminescence can be generated in an excitation source free manner, which allows for a significant reduction in background noise and for the use of an optical setup that comprises only a detection element. Here, we develop a highly-sensitive protein quantification platform by combining chemiluminescent detection of proteins with microfluidic mixing and detection. We use the platform to demonstrate quantitative detection of proteins over a concentration range of five orders of magnitude </p> <p>and down to 10 pg mL−1, corresponding to pM concentrations. Owing to the general presence of amine groups in peptides and proteins, our demonstrated system is applicable to characterising any protein sample and it can be used to quantify unlabelled samples. </p> </div> </div> </div>

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Real-Time Highly-Sensitive Protein Quantification Through On-Chip Chemiluminescence

10.26434/chemrxiv.12646376 ◽

2020 ◽

Author(s):

Hoi Kei Chiu ◽

Tadas Kartanas ◽

Sean R. A. Devenish ◽

Kadi Saar ◽

Carina Mouritsen Luxhøj ◽

...

Keyword(s):

Background Noise ◽

Protein Quantification ◽

Quantitative Detection ◽

Background Signal ◽

Microfluidic Mixing ◽

Highly Sensitive ◽

Amine Groups ◽

On Chip ◽

Highly Sensitive Detection ◽

Illumination Source

<div> <div> <div> <p>A range of experimental methods have been developed to achieve highly sensitive detection and quantification of proteins. The majority of these methods rely on fluorescence-mediated readouts and, as such, their sensitivity can be affected by factors such as photobleaching of fluorophores and background signal from the illumination source. Both of these limitations can be overcome by using chemiluminescence-based detection: in contrast to fluorescence, chemiluminescence can be generated in an excitation source free manner, which allows for a significant reduction in background noise and for the use of an optical setup that comprises only a detection element. Here, we develop a highly-sensitive protein quantification platform by combining chemiluminescent detection of proteins with microfluidic mixing and detection. We use the platform to demonstrate quantitative detection of proteins over a concentration range of five orders of magnitude </p> <p>and down to 10 pg mL−1, corresponding to pM concentrations. Owing to the general presence of amine groups in peptides and proteins, our demonstrated system is applicable to characterising any protein sample and it can be used to quantify unlabelled samples. </p> </div> </div> </div>

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Inkjet-printed point-of-care immunoassay on a nanoscale polymer brush enables subpicomolar detection of analytes in blood

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1703200114 ◽

2017 ◽

Vol 114 (34) ◽

pp. E7054-E7062 ◽

Cited By ~ 41

Author(s):

Daniel Y. Joh ◽

Angus M. Hucknall ◽

Qingshan Wei ◽

Kelly A. Mason ◽

Margaret L. Lund ◽

...

Keyword(s):

Polymer Brushes ◽

High Performance ◽

Point Of Care ◽

Polymer Brush ◽

Quantitative Detection ◽

Figures Of Merit ◽

Point Of Care Test ◽

Resource Limited ◽

Multiple Analytes ◽

On Chip

The ELISA is the mainstay for sensitive and quantitative detection of protein analytes. Despite its utility, ELISA is time-consuming, resource-intensive, and infrastructure-dependent, limiting its availability in resource-limited regions. Here, we describe a self-contained immunoassay platform (the “D4 assay”) that converts the sandwich immunoassay into a point-of-care test (POCT). The D4 assay is fabricated by inkjet printing assay reagents as microarrays on nanoscale polymer brushes on glass chips, so that all reagents are “on-chip,” and these chips show durable storage stability without cold storage. The D4 assay can interrogate multiple analytes from a drop of blood, is compatible with a smartphone detector, and displays analytical figures of merit that are comparable to standard laboratory-based ELISA in whole blood. These attributes of the D4 POCT have the potential to democratize access to high-performance immunoassays in resource-limited settings without sacrificing their performance.

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