Novel Amperometric Xanthine Biosensors Based on REGO-NP (Pt, Pd, and Au) Bionanocomposite Film

Amperometric biosensor was fabricated using nanocomposite film which is constructed by separate embedding of reduced expanded graphene oxide (REGO), REGO-gold, REGO-palladium, and REGO-platinum into poly(glycidyl methacrylate-co-vinylferrocene) (P(Vfc(0.4)-GMA)), and by covalent immobilization of xanthine oxidase (XOD) on the surface of nanocomposite-coated electrode. Using these tailored nanocomposites and surface binding of XOD, it has been systematically studied to obtain optimum and most ideal system for xanthine detection in real samples. The best performance in xanthine detection was REGO-platinum-based nanocomposite electrode which is able to detect xanthine with sensitivity of 21.98 mu A/mu M it has linear range of 1 to 40 mu M, low detection limit of 0.003 mu M, and excellent response time of 2 s. At the end, fabricated electrode was subjected to real sample testing by measuring xanthine concentration in chicken and meat. Biosensor was found to be very reliable and with minimum interference applicable in meat freshness control as well.