Development of a Non-Enzymatic Glucose Sensor Based on Fe <sub>2</sub> O <sub>3</sub> Nanoparticles-Carbon Paste Electrodes
D. Hernández-Ramírez, Luis Humberto Mendoza-Huízar, Carlos Andrés Galán-Vidal, Guadalupe Yoselín Aguilar-Lira, G. A. Álvarez-Romero
Abstract
Fe 2 O 3 nanoparticles have interesting properties such as low production cost, chemical stability, biocompatibility, poor toxicity and high conductivity. In this work, Fe 2 O 3 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 Fe 2 O 3 -NPs/CPE sensor showed excellent electro-catalytic performance towards glucose oxidation and three linear ranges: 0.015 μ M–1 μ M (sensitivity of 51.54 μ A/ μ M), 1 μ M–100 μ M (sensitivity of 4.21 μ A/ μ M) and, 30 μ M–700 μ M (sensitivity of 0.041 μ A μ M −1 ) and detection limit of 0.044 μ M. 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 Fe 2 O 3 -NPs/CPE is attributed to the formation of Fe 4+ = O reactive groups at alkaline pH that allowed the oxidization of glucose by a nonenzymatic mechanism.