Flow-Injection Amperometric Determination of Glucose Using Nickel Oxide-Cobalt (II,III) Oxide and Nickel Oxide-Copper Nanoparticle Modified Pencil Graphite Electrodes

This study features an enzyme-free amperometric determination of glucose with flow injection analysis (FIA) using pencil graphite electrodes (PGEs) modified with nickel oxide-cobalt (II,III) oxide (NiO-Co3O4/PGE) and nickel oxide-copper nanoparticle (NiO-CuNPs/PGE). Both modified PGEs exhibited excellent electrocatalytic activity toward oxidation of glucose in strong alkaline media since they enhanced the peak current compared with the bare PGE and single metal oxide- or metal nanoparticle-modified PGEs. Flow-injection (FI) amperometry showed the linear response range, the limit of detection and sensitivity for NiO-Co3O4/PGE and NiO-CuNPs/PGE were 1.0-1000 mu M, 0.23 mu M and 586 mu A mM(-1) cm(-2), and 0.10-250 mu M, 0.03 mu M and 949 mu A mM(-1) cm(-2), respectively. Glucose was determined in real samples with good accuracy and precision.