Electrochemical deposition of GO-PANI@Pt-Ir film for non-enzymatic electrochemical oxidation of glucose

In this study, a composite electrode was developed for non-enzymatic glucose oxidation, consisting of a polyaniline (PANI) film modified with graphene oxide (GO) on a platinum-iridium (Pt-Ir) substrate (GO-PANI@Pt-Ir). GO was synthesized by a modified Hummers approach, and the composite coating was formed through electrochemical polymerization of aniline in 0.5 M H2SO4. The process conditions were optimized using response surface methodology (RSM) in two phases. In the first phase, the influences of scan rate (20–100 mV/s), number of cycles (20–100), GO content (1–3 mg/mL), and aniline concentration (0.1–0.3 M) were evaluated for the oxidation of 0.5 mM glucose. Optimal electrode fabrication obtained at 2.5 mg/mL GO, 0.25 M aniline, 60 mV/s, and 40 cycles. In the second phase, the effects of glucose concentration (0.5–2.5 mM), applied potential (0.5–1.5 V), and temperature (20–60 °C) were examined. The highest glucose removal (310.17 µM) occurred at 1.8 mM glucose, +1.1 V, and 25 °C, producing gluconic acid as the dominant product. Kinetic analysis indicated a pseudo-second-order (PSO) model consistent with Langmuir-Hinshelwood (L-H) kinetic model, with the surface reaction step being rate-limiting. GO-PANI@Pt-Ir electrode thus exhibits promising electrocatalytic behavior for environmental electrochemical applications.