Disposable biosensor based on immobilisation of glutamate oxidase on Pt nanoparticles modified Au nanowire array electrode

Novel electrochemical platform based on Pt nanoparticle modified ordered three-dimensional gold nanowire arrays (PtNP/NAEs) for the amperometric sensing of H₂O₂ and glutamate is developed. Pt nanoparticle (PtNP) is fabricated by electrodeposition onto the 3D nanowires and characterised using scanning electron microscopy (SEM) and cyclic voltammetry. The deposited nanoparticles have an average size of 20nm. The PtNP/NAE shows a linear response of up to 20mM for H₂O₂ detection with a sensitivity of 194.60μAmM^-1cm^-2 at 20°C. It can detect 1μM (S/N=3) of H₂O₂ at normal condition without using any enzyme or mediator. Analytical performance of this electrode is tested by immobilising glutamate oxidase (GlutOx) through cross-linking in the matrix of bovine serum albumin (BSA), Nafion and glutaraldehyde. At physiological pH, the biosensor showed the sensitivity of 10.76μAmM^-1cm^-2, with a linear range of up to 0.8mM.