Microfluidic fabric-based electrochemical device for detection of clinical analytes in physiological fluids

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Date
2014
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Publisher
Universiti Teknologi Malaysia
Abstract
In recent years, inexpensive alternative materials (paper, yarn/thread and fabric) have been proposed for the construction of new generation of point-of-care (POC) microfluidic diagnostic devices. The purpose of this study is to investigate the integration of electrochemical detection in fabric-based microfluidic device for quantitative measurement of biomarkers in physiological fluids. The device was fabricated using two methods, template for patterning the electrodes and wax-patterning for creating the hydrophilic/hydrophobic contrast. The electrodes incorporated within the fabricated device were evaluated using cyclic voltammetry. The feasability of the device to determine clinical analytes such as glucose, lactate and ascorbic acid (AA) in control serum, saliva and artificial urine samples, respectively was demonstrated using chronoamperometry at the optimal detection potential (-0.2 V vs. Ag/AgCl for glucose and lactate; 0.28 V vs. Ag/AgCl for AA). The levels of the analytes measured were within the margin of error of the actual concentrations. The sensitivity of the device for the determination of glucose, lactate and AA were 0.294 ± 0.082, 0.3169 ± 0.099 and 0.4202 ± 0.229 |iA/mM, respectively, which are within the physiological range (2 to 25, 0.1 to 5 and 0.5 to 10 mM, respectively) of these analytes. The influence of mechanical stress towards the morphology and electrochemical behaviour were examined for both microfluidic fabric-based electrochemical device (^FED) and microfluidic paper-based electrochemical device (^PED). The results implied that the proposed |iFED was more durable under mechanical stress (sensitivity drop of ~ 21.6%) in comparison to the |iPED (sensitivity drop of ~ 48.6%). A three dimensional (3D) |iFED prototype for sample collection and continuous assessment (t = 170 min) of dynamic electrochemical measurement was also developed and evaluated. The |iFED provided an efficient sample delivery towards the reaction chamber, allowing dynamic electrochemical measurement in real-time without interruption unlike the |iPED. This study shows the potential of the proposed |iFED as a novel microfluidic sensing platform for a variety of assays that require simplicity, low-cost, portability, flexibility and continuous real-time monitoring
Description
Thesis (Ph.D (Biomedical Engineering))
Keywords
Biosciences and medical engineering
Citation