Facile and Rapid One-step Mass Production of Flexible 3D Porous Graphene Nanozyme Electrode via Direct Laser-writing for Intelligent Evaluation of Fish Freshness

Abstract In this report, we have prepared 3D porous graphene flexible nanozyme electrode on polyimide by direct laser-writing technology using a home-made computer-controlled laser scribing machine, which is a cost-efficient and one-step mass-production method. This flexible electrode exhibited outstanding mechanical flexibility, distinctive 3D porous structure, expected cycle stability, high conductivity, which was employed as a novel electrochemical nano-sensing platform for intelligent evaluation of fish freshness via simultaneous detection of both xanthine (XT) and hypoxanthine (HX) and smart analysis and digital output using machine learning (ML) model based on artificial neural network (ANN) algorithm. The as-prepared flexible electrode showed an enzyme-like kinetic (nanozyme) characteristic during the detection of XT (0.3 – 179.9 μM) and HX (0.3 – 159.9 μM) with a limit of detection (LOD) of 0.26 μM and 0.18 μM, respectively. The fish freshness was evaluated by voltammetric detection of both XT and HX in fish sample with different storage times, and ML model with ANN algorithm was built to realize smart analysis and digital output for evaluating the fish freshness. This will provide an experimental support for biomimetic flexible nano-sensing platform based on nanozyme flexible electrode via facile and rapid one-step mass production and intelligent nano-sensing platform based on ML model for intelligent operation for smart analysis and intelligent transformation for digital output.