Construction of Cu2O/PANI-GO/SS flexible electrode with three-dimensional network structure towards electrochemical sensing of glucose and ascorbic acid

Three-dimensional (3D) nanostructures which have the ability to expand carrier diffusion channels and provide plenty of electrocatalytic active sites are extensively regarded as highly effective strategies for enhancing the sensing performance of electrocatalysts. Herein, a highly sensitive Cu 2 O/PANI-GO electrode was constructed simply via in-situ electrodeposition of the graphene oxide (GO) doped polyaniline PANI (PANI-GO) 3D porous network structure on a flexible stainless-steel (SS) foil substrate. Subsequently, Cu₂O nanoparticles were electrodeposited onto the unique 3D network architecture which provides abundant active sites for Cu 2 O deposition. Meanwhile, the introduction of conductive PANI and GO improves the conductivity of the sensing catalysts and enhances the electrocatalytic performance of Cu 2 O. The electrochemical behavior of glucose and ascorbic acid (AA) was investigated through cyclic voltammetry (CV). CV results have demonstrated that the formation of a 3D porous network structure provides a substantial number of electronic pathways, which facilitate direct electron transfer between biomolecules and electrocatalysts, thereby promoting the electrocatalytic oxidation of glucose and ascorbic acid (AA). According to chronoamperometry, such a 3D porous network structure electrode exhibits outstanding sensing performance for glucose and AA detection, including lower detection limit and higher sensitivity over a wide detection range compared with the reported similar Cu 2 O-based electrodes. The excellent anti-interference, stability, reproducibility, and bending stability are also obtained. Furthermore, the glucose concentration in diluted fetal bovine serum and AA concentration in diluted vitamin c beverages were quantitatively measured, and the results were satisfactory, indicating that the proposed flexible electrochemical sensing electrode provides considerable prospects for practical human health and food safety monitoring.