Layer-by-layer Fabrication of Gold Nanoparticles/Polyaniline Modified Gold Electrodes for Direct Non-enzymatic Oxidation of Glucose

Background: Non-enzymatic direct glucose biofuel cell is a promising technology to harness sustainable renewable energy. Furthermore, monitoring glucose levels is essential for human lives with age. Thus, there is an increasing need to develop highly efficient and stable modified electrodes. Methods: This study reported the manufacture of gold nanoparticles/polyaniline/modified gold electrodes (Au NPs/PANI/Au electrode) based on the electrochemical polymerization method followed by the deposition of gold nanoparticles. The shapes and chemical constitution of the electrodes were examined by using different techniques including SEM, FTIR, XRD, EDS, and Raman spectroscopy techniques. The electrocatalytic efficiency of the present electrodes toward direct glucose oxidation was evaluated by applying cyclic voltammetry, linear sweep voltammetry, and square wave voltammetry techniques. Results: The results exhibited high electrocatalytic performance for direct glucose electrooxidation in alkaline media. The modified electrodes show the ability to electrooxidation of various glucose concentrations (1 μM 100 μM) with a limit of detection and limit of quantitation of 140 nM and 424 nM, respectively. Furthermore, the Au NPs/PANI/Au electrode showed higher durability, sensitivity, and selectivity toward glucose oxidation than the Au NPs/ Au electrode, which confirmed the role of the PANI layer in enhancing the stability of the modified electrode. Conclusion: Moreover, the molar fraction of glucose to KOH has a crucial role in the output current. Hence, the modified electrodes are great candidates for direct glucose biofuel cell application.