Self-assembled enzyme biosensors based on xanthine oxidase (XO) and CS@GO for screening natural products for anti-gout active ingredients

Gout is a joint disease caused by the deposition of monosodium urate, the incidence of which shows an escalating trend annually while demonstrating a propensity toward younger populations, whereas available pharmacological interventions frequently induce severe adverse effects. In this investigation, a highly sensitive electrochemical enzyme biosensor was constructed based on the pivotal role of xanthine oxidase (XO); the enzymatic activity was enhanced through chitosan - functionalized graphene oxide (CS@GO)-modified electrodes coupled with electrodeposited gold nanoparticles (AuNPs), which, when integrated with their superior electrical conductivity along with exceptional biocompatibility, facilitated the highly efficient screening of anti-gout components within natural products. Following optimization of critical parameters, evaluation of 14 compounds revealed five plant extracts (accounting for 28 % of samples) exhibiting XO inhibition exceeding 83 %, demonstrating superior efficacy compared to allopurinol (83.32 %). This methodology establishes an innovative strategy for rapid identification of highly potent yet minimally toxic anti-gout natural compounds, offering significant reference value regarding natural drug development.