MICROFLOW ELECTROCHEMICAL DETECTION ON CLOTH-BASED DEVICE

Abstract

A continuous flow-electrochemical microfluidic cloth-based device (CF-eµCAD) has been developed to create microflow injection analysis (µFIA) system with integrated electrochemical detection on the cloth-based device (CAD). The µCAD was designed to have a long channel to allow the capillary flow and fabricated by polymer screen-printing method using polystyrene as a hydrophobic material. The electrode was screen-printed on the CAD at the end of the channel using silver-silver chloride, carbon paste modified with Prussian blue, and carbon paste as reference, working, and auxiliary electrodes, respectively. A µFIA system is created by immersing the top end in a microtube containing the carrier solution. The area next to the electrode is inclined at an angle of 45 degrees to the plane and the end of the channel is dipped in the lower reservoir. The flow analysis was performed by injecting the analyte at the sample injection zone which is located 1.0 cm away from the reference electrode. The solution flowed on the CAD by the capillary wicking, and the gravitational force from the carrier's upper reservoir and pushed the analyte to pass through the electrodes to the lower reservoir. Under optimal conditions, the system was applied for analysis of H2O2, glucose and pesticide in food, human serum and rice field water sample, respectively. The method provided accurate analysis of these analyte comparable to the traditional methods or certified values. These results indicated that the developed CF-eµCAD can served as an analytical platform that can be applicable in a wide range of chemical analysis and can be extensively used in the future.

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