An Electrochemical Sensor for Glucose Detection

Abstract

This thesis presents a report on a non-enzymatic electrochemical sensor consisting of a screen-printed carbon electrode (SPCE) modified with graphene oxide- poly(acrylic acid)-palladium nanoparticles (GO-PAA-PdNPs). The sensor was used in a system to determine glucose concentration by flow injection amperometry (FI-Amp). PdNPs were synthesized on GO-PAA by electroless deposition. The GO-PAA-PdNP- modified SPCE showed excellent electrocatalytic performance for the oxidation of glucose. The surface morphology of the modified electrode was characterized by transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) spectroscopy. The electrochemical behaviors of glucose on the different modified surfaces were also studied by cyclic voltammetry and amperometry. To achieve the optimal electrocatalytic oxidation of glucose at the GO-PAA-PdNPs/SPCE, amount of GO-PAA-PdNPs, the applied potential, sample volume and flow rate of the Fl-Amp system were optimized. Under the optimal conditions, the current response when the glucose standard was injected provided a detection limit of 22 μmol L ́1, a limit of quantitation of 76 μmol L ́1 and two linear ranges: 50 to 15,000 μmol L1 and 15,000 to 60,000 μmol L1. This sensor had excellent sensitivity, good repeatability and high selectivity. The fabricated sensor was applied to detect glucose in biological fluid samples, and the results were in good agreement with those obtained from the standard hexokinase-spectrophotometric clinical method.