Development of a Non-Enzymatic Glucose Sensor Based on Fe2O3 Nanoparticles-Carbon Paste Electrodes

Abstract

Fe2O3 nanoparticles have interesting properties such as low production cost, chemical stability, biocompatibility, poor toxicity and high conductivity. In this work, Fe2O3 nanoparticles are used as modifiers to combine its characteristics to those of carbon paste electrodes to enhance the determination of glucose. Differential pulse voltammetry was used as the quantitative analytical technique and then, a Box-Behnken design was used to optimize the its variables in order to maximize the glucose electro-oxidation response signal. The Fe2O3-NPs/CPE sensor showed excellent electro-catalytic performance towards glucose oxidation and three linear ranges: 0.015 μM–1 μM (sensitivity of 51.54 μA/ μM), 1 μM–100 μM (sensitivity of 4.21 μA/μM) and, 30 μM–700 μM (sensitivity of 0.041 μA μM−1) and detection limit of 0.044 μM. The sensor also presented good reproducibility and repeatability, excellent selectivity (in the presence of ascorbic acid, uric acid, lactose, caffeine, and paracetamol), and satisfactory applicability for glucose detection in commercial electrolyte beverages and human urine samples. The improved electrochemical detection capability of Fe2O3-NPs/CPE is attributed to the formation of Fe4+ = O reactive groups at alkaline pH that allowed the oxidization of glucose by a nonenzymatic mechanism.