DEVELOPMENT OF AN AMPEROMETRIC GLUTAMATE-SENSITIVE BIOSENSOR BASED ON GLUTAMATE OXIDASE ADSORBED ON SILICALITE

In the current work, a new design of an amperometric biosensor for highly sensitive and selective detection of glutamate was developed using an atypical method of immobilizing glutamate oxidase (GlOX) by adsorption onto silicalite nanoparticles. The procedure for manufacturing the biosensor was optimized, namely, the main parameters of the modification of amperometric platinum transducers with a layer of silicalite nanoparticles were determined, and the optimal conditions for GlOX adsorption on this layer were also selected. Biosensors based on GlOX adsorbed on silicalite demonstrated high sensitivity to low concentrations of glutamate. The linear detection range was from 2.5 μM to 450 μM, and the detection limit of glutamate was 1 μM. It was also shown in the work that the proposed biosensors are characterized by high reproducibility of responses during several hours of continuous operation (RSD up to 7%) and good operational stability for several days. After carrying out the entire complex of works on the development and optimization of a new glutamate-sensitive biosensor, it was found that sensors of this design with the declared analytical characteristics can be used to determine low concentrations of glutamate in real biological fluids.