scholarly journals Smart Integrated Sensor for Multiple Detections of Glucose and L-Lactate Using On-Chip Electrochemical System

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Tomoyuki Yamazaki ◽  
Takaaki Ikeda ◽  
Byounghyun Lim ◽  
Koichi Okumura ◽  
Makoto Ishida ◽  
...  
Keyword(s):  
Point Of Care ◽  
Reference Electrode ◽  
Electrochemical Sensing ◽  
Quantitative Detection ◽  
Enzymatic Reactions ◽  
Single Chip ◽  
Lactate Oxidase ◽  
Integrated Sensor ◽  
System L ◽  
On Chip

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.

scholarly journals Printable graphene BioFETs for DNA quantification in Lab-on-PCB microsystems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sotirios Papamatthaiou ◽  
Pedro Estrela ◽  
Despina Moschou
Keyword(s):  
Printed Circuit Board ◽  
Point Of Care ◽  
Dna Amplification ◽  
Electrochemical Sensing ◽  
Circuit Board ◽  
Label Free ◽  
Transistor Channel ◽  
Lab On Chip ◽  
Passive Electrode ◽  
On Chip

AbstractLab-on-Chip is a technology that aims to transform the Point-of-Care (PoC) diagnostics field; nonetheless a commercial production compatible technology is yet to be established. Lab-on-Printed Circuit Board (Lab-on-PCB) is currently considered as a promising candidate technology for cost-aware but simultaneously high specification applications, requiring multi-component microsystem implementations, due to its inherent compatibility with electronics and the long-standing industrial manufacturing basis. In this work, we demonstrate the first electrolyte gated field-effect transistor (FET) DNA biosensor implemented on commercially fabricated PCB in a planar layout. Graphene ink was drop-casted to form the transistor channel and PNA probes were immobilized on the graphene channel, enabling label-free DNA detection. It is shown that the sensor can selectively detect the complementary DNA sequence, following a fully inkjet-printing compatible manufacturing process. The results demonstrate the potential for the effortless integration of FET sensors into Lab-on-PCB diagnostic platforms, paving the way for even higher sensitivity quantification than the current Lab-on-PCB state-of-the-art of passive electrode electrochemical sensing. The substitution of such biosensors with our presented FET structures, promises further reduction of the time-to-result in microsystems combining sequential DNA amplification and detection modules to few minutes, since much fewer amplification cycles are required even for low-abundance nucleic acid targets.

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

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>

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

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>

scholarly journals On-Chip Inverted Emulsion Method for Fast Giant Vesicle Production, Handling, and Analysis

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 285 ◽  
Author(s):  
Naresh Yandrapalli ◽  
Tina Seemann ◽  
Tom Robinson
Keyword(s):  
Microfluidic Chip ◽  
Enzymatic Reactions ◽  
Single Chip ◽  
Artificial Cells ◽  
Observation Chamber ◽  
Emulsion Method ◽  
Solution Exchange ◽  
Fast Solution ◽  
On Chip ◽  
Single Batch

Liposomes and giant unilamellar vesicles (GUVs) in particular are excellent compartments for constructing artificial cells. Traditionally, their use requires bench-top vesicle growth, followed by experimentation under a microscope. Such steps are time-consuming and can lead to loss of vesicles when they are transferred to an observation chamber. To overcome these issues, we present an integrated microfluidic chip which combines GUV formation, trapping, and multiple separate experiments in the same device. First, we optimized the buffer conditions to maximize both the yield and the subsequent trapping of the vesicles in micro-posts. Captured GUVs were monodisperse with specific size of 18 ± 4 µm in diameter. Next, we introduce a two-layer design with integrated valves which allows fast solution exchange in less than 20 s and on separate sub-populations of the trapped vesicles. We demonstrate that multiple experiments can be performed in a single chip with both membrane transport and permeabilization assays. In conclusion, we have developed a versatile all-in-one microfluidic chip with capabilities to produce and perform multiple experiments on a single batch of vesicles using low sample volumes. We expect this device will be highly advantageous for bottom-up synthetic biology where rapid encapsulation and visualization is required for enzymatic reactions.

scholarly journals Electrochemical Discrimination of Salbutamol from Its Excipients in VentolinTM at Nanoporous Gold Microdisc Arrays

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3975
Author(s):  
Lorraine C. Nagle ◽  
Amelie Wahl ◽  
Vladimir Ogourstov ◽  
Ian Seymour ◽  
Fiona Barry ◽  
...  
Keyword(s):  
Reference Electrode ◽  
Linear Sweep Voltammetry ◽  
Nanoporous Gold ◽  
Electrochemical Sensing ◽  
Electrode Arrays ◽  
Fully Integrated ◽  
Embedded Sensing ◽  
Sensing Platform ◽  
On Chip ◽  
Novel Algorithms

The emergence of specific drug–device combination products in the inhalable pharmaceutical industry demands more sophistication of device functionality in the form of an embedded sensing platform to increase patient safety and extend patent coverage. Controlling the nebuliser function at a miniaturised, integrated electrochemical sensing platform with rapid response time and supporting novel algorithms could deliver such a technology offering. Development of a nanoporous gold (NPG) electrochemical sensor capable of creating a unique fingerprint signal generated by inhalable pharmaceuticals provided the impetus for our study of the electrooxidation of salbutamol, which is the active bronchodilatory ingredient in VentolinTM formulations. It was demonstrated that, at NPG-modified microdisc electrode arrays, salbutamol is distinguishable from the chloride excipient present at 0.0154 M using linear sweep voltammetry and can be detected amperometrically. In contrast, bare gold microdisc electrode arrays cannot afford such discrimination, as the potential for salbutamol oxidation and chloride adsorption reactions overlap. The discriminative power of NPG originates from the nanoconfinement effect for chloride in the internal pores of NPG, which selectively enhances the electron transfer kinetics of this more sluggish reaction relative to that of the faster, diffusion-controlled salbutamol oxidation. Sensing was performed at a fully integrated three-electrode cell-on-chip using Pt as a quasi-reference electrode.

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

2017 ◽  
Vol 114 (34) ◽  
pp. E7054-E7062 ◽  
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.

scholarly journals Integration of Biosensors and Associated Electronics on Lab-on-Chip Devices

1970 ◽  
Vol 110 (4) ◽  
pp. 61-66
Author(s):  
A. T. Giannitsis ◽  
T. Parve ◽  
M. Min
Keyword(s):  
Environmental Monitoring ◽  
Point Of Care ◽  
Single Chip ◽  
Sensing Element ◽  
Lab On Chip ◽  
Liquid Samples ◽  
On Chip ◽  
Miniaturized Devices

Lab-on-chip devices comprise a class of bioelectronic miniaturized devices that incorporate microfluidic and biosensing apparatuses on a single chip. They are dedicated for analyzing and processing biochemical liquid samples, which may consist of enzymes, proteins, nucleotides, or even cells and viruses. Furthermore, lab-on-chips may enhance synthesis of biochemical products. The importance of lab-on-chip devices lies on their potentiality of advancing the development of environmental monitoring sensors and also point-of-care analyzers in medicine. This article presents the usual microfabrication methods for manufacturing lab-on-chip devices, with emphasis on the integration of the biosensor, the biocompatibility of the sensing element of the biosensor, and the essential electronics. Three major types of biosensors are analyzed: optical, impedimetric and electrochemical ones. Ill. 7, bibl. 28 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.110.4.288

scholarly journals Design and Fabrication of Multichannel PDMS Microfluidic

2021 ◽  
Vol 2129 (1) ◽  
pp. 012048
Author(s):  
M N Afnan Uda ◽  
U Hashim ◽  
M N A Uda ◽  
N A Parmin ◽  
V Thivina
Keyword(s):  
Contact Area ◽  
Microfluidic Chip ◽  
Point Of Care ◽  
Main Tool ◽  
Morphological Properties ◽  
Single Chip ◽  
Lab On Chip ◽  
Micro Channels ◽  
On Chip ◽  
Disease Analysis

Abstract Microfluidic delivers miniaturized fluidic networks for processing liquids in the microliter range. In the recent years, lab-on-chip (LOC) is become a main tool for point-of-care (POC) diagnostic especially in the medical field. In this paper, we presented a design and fabrication on multi disease analysis using single chip via delivery of fluid with the multiple transducers is the pathway of multi-channel microfluidic based LOC’s. 3 in 1 nano biosensor kit was attached with the microfluidic to produce nano-biolab-on-chip (NBLOC). The multi channels microfluidic chip was designed including the micro channels, one inlet, three outlet and sensor contact area. The microfluidic chip was designed to include multiplex detection for pathogen that consists of multiple channels of simultaneous results. The LOC system was designed using Design Spark Mechanical software and PDMS was used as a medium of the microfluidic. The microfluidic mold and PDMS microfluidic morphological properties have been characterized by using low power microscope (LPM), high power microscope (HPM) and surface profiler. The LOC system physical was experimental by dropping food coloring through the inlet and collecting at the sensor contact area outlet.

scholarly journals Electrochemical multi-analyte point-of-care perspiration sensors using on-chip three-dimensional graphene electrodes

2020 ◽  
Author(s):  
Meike Bauer ◽  
Lukas Wunderlich ◽  
Florian Weinzierl ◽  
Yongjiu Lei ◽  
Axel Duerkop ◽  
...  
Keyword(s):  
Response Time ◽  
Large Scale ◽  
Electrochemical Impedance ◽  
Point Of Care ◽  
Three Dimensional ◽  
Reference Electrode ◽  
Amperometric Detection ◽  
Fast Response ◽  
Electrochemical Sensing ◽  
Electron Mediator

Abstract Multi-analyte sensing using exclusively laser-induced graphene (LIG)-based planar electrode systems was developed for sweat analysis. LIG provides 3D structures of graphene, can be manufactured easier than any other carbon electrode also on large scale, and in form of electrodes: hence, it is predestinated for affordable, wearable point-of-care sensors. Here, it is demonstrated that LIG facilitates all three electrochemical sensing strategies (voltammetry, potentiometry, impedance) in a multi-analyte system for sweat analysis. A potentiometric potassium-ion-selective electrode in combination with an electrodeposited Ag/AgCl reference electrode (RE) enabled the detection of potassium ions in the entire physiologically relevant range (1 to 500 mM) with a fast response time, unaffected by the presence of main interfering ions and sweat-collecting materials. A kidney-shaped interdigitated LIG electrode enabled the determination of the overall electrolyte concentration by electrochemical impedance spectroscopy at a fixed frequency. Enzyme-based strategies with amperometric detection share a common RE and were realized with Prussian blue as electron mediator and biocompatible chitosan for enzyme immobilization and protection of the electrode. Using glucose and lactate oxidases, lower limits of detection of 13.7 ± 0.5 μM for glucose and 28 ± 3 μM for lactate were obtained, respectively. The sensor showed a good performance at different pH, with sweat-collecting tissues, on a model skin system and furthermore in synthetic sweat as well as in artificial tear fluid. Response time for each analytical cycle totals 75 s, and hence allows a quasi-continuous and simultaneous monitoring of all analytes. This multi-analyte all-LIG system is therefore a practical, versatile, and most simple strategy for point-of-care applications and has the potential to outcompete standard screen-printed electrodes.

scholarly journals PERFORMANCE CHARACTERISTICS OF A FRET-BASED IMMUNOASSAY FOR QUANTITATION OF INFLIXIMAB ON A POINT-OF-CARE INSTRUMENT SYSTEM

2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S57-S57
Author(s):  
Edgar Ong ◽  
Ruo Huang ◽  
Richard Kirkland ◽  
Michael Hale ◽  
Larry Mimms
Keyword(s):  
Whole Blood ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Quantitative Detection ◽  
Therapeutic Drug ◽  
Analytical Sensitivity ◽  
Sample Type ◽  
Hook Effect ◽  
Limit Of Quantitation ◽  
Assay Precision

Abstract Introduction A fast (&lt;5 min), time-resolved fluorescence resonance energy transfer (FRET)-based immunoassay was developed for the quantitative detection of infliximab (IFX) and biosimilars for use in therapeutic drug monitoring using only 20 µL of fingerstick whole blood or serum at the point-of-care. The Procise IFX assay and ProciseDx analyzer are CE-marked. Studies were performed to characterize analytical performance of the Procise IFX assay on the ProciseDx analyzer. Methods Analytical testing was performed by spiking known amounts of IFX into negative serum and whole blood specimens. Analytical sensitivity was determined using limiting concentrations of IFX. Linearity was determined by testing IFX across the assay range. Hook effect was assessed at IFX concentrations beyond levels expected to be found within a patient. Testing of assay precision, cross-reactivity and potential interfering substances, and biosimilars was performed. The Procise IFX assay was also compared head-to-head with another CE-marked assay: LISA-TRACKER infliximab ELISA test (Theradiag, France). The accuracy of the Procise IFX assay is established through calibrators and controls traceable to the WHO 1st International Standard for Infliximab (NIBSC code: 16/170). Results The Procise IFX assay shows a Limit of Blank, Limit of Detection, and Lower Limit of Quantitation (LLoQ) of 0.1, 0.2, and 1.1 µg/mL in serum and 0.6, 1.1, and 1.7 µg/mL in whole blood, respectively. The linear assay range was determined to be 1.7 to 77.2 µg/mL in serum and whole blood. No hook effect was observed at an IFX concentration of 200 µg/mL as the value reported as “&gt;ULoQ”. Assay precision testing across 20 days with multiple runs and reagent lots showed an intra-assay coefficient of variation (CV) of 2.7%, an inter-assay CV of &lt;2%, and a total CV of 3.4%. The presence of potentially interfering/cross-reacting substances showed minimal impact on assay specificity with %bias within ±8% of control. Testing of biosimilars (infliximab-dyyb and infliximab-abda) showed good recovery. A good correlation to the Theradiag infliximab ELISA was obtained for both serum (slope=1.01; r=0.99) and whole blood (slope=1.01; r=0.98) samples (Figure 1). Conclusion Results indicate that the Procise IFX assay is sensitive, specific, and precise yielding results within 5 minutes from both whole blood and serum without the operator needing to specify sample type. Additionally, it shows very good correlation to a comparator assay that takes several hours and sample manipulation to yield results. This makes the Procise IFX assay ideal for obtaining fast and accurate IFX quantitation, thus allowing for immediate drug level dosing decisions to be made by the physician during patient treatment.

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