Combination of few-layer bismuthene and glutamate dehydrogenase for enhanced glutamate biosensing

This work reports the development of an enzymatic electrochemical biosensor for glutamate detection based on few-layer bismuthene hexagons (FLB), a two-dimensional nanomaterial with outstanding electrocatalytic and biocompatible properties. FLB was synthesized by a wet chemistry method and integrated into screen-printed graphene electrodes (SPGrE) to provide a stable and biocompatible conductive surface for the immobilization of redox enzyme glutamate dehydrogenase (GLDH). The combination of FLB with GLDH enabled the efficient electrochemical detection of glutamate through the oxidation of enzymatically generated NADH. The resulting nanostructured biosensing platform exhibits a wide linear detection range (6.54–125 μM), a low detection limit (1.96 μM), and high selectivity toward common interfering compounds. Each step of the bioplatform fabrication was characterized using electrochemical, microscopic and spectroscopic techniques, confirming the successful immobilization of FLB and GLDH. The applicability of the biosensor was further validated by glutamate determination in human serum and food samples, demonstrating excellent analytical performance and storage stability over 20 days. These results highlight the potential of FLB as a key nanomaterial for the development of highly sensitive and selective enzymatic electrochemical biosensors.