Developing a point-of-care System for Determination of Dopamine, Ascorbic and Uric Acids in Biological Fluids Using a Screen-Printed Electrode Modified by Three Dimensional Graphene/Carbon Nanotube Hybrid

摘要

A cost-effective point-of-care (POC) device including a potentiostat, a modified screen printed electrode(SPE) placed in a custom-designed microfluidic chamber, and a homemade syringe pump setup wasdeveloped as an electrochemical assay for determination of dopamine (DA), ascorbic acid (AA), anduric acid (UA) in human plasma and urine. SPE was modified with three-dimensional graphene/carbonnanotube (3DG/CNT) used as a new electrochemical sensor. A microcontroller-based potentiostat wasdeveloped to perform cyclic voltammetry (CV) and differential pulse voltammetry (DPV)measurements. The syringe pump system based on open source electronics was made to guide thesolution through a microfluidic chamber. In order to improve the quantification accuracy, the DPV peakswere resolved, using partial least square (PLS) method. The detection limits were AA (2.5 μM), DA (0.4μM), and UA (0.6 μM) (signal to noise ratio, 3). The linear dynamic ranges were 4-2000, 0.5-2000, and0.8-1500 μM for DA, AA, and UA, respectively. The precision of the method (RSD, n=3) was < 2.2 %.