Highly selective and stable glucose biosensor based on incorporation of platinum nanoparticles into polyaniline-montmorillonite hybrid composites

The selectivity and stability of biosensor are still challenging goal. Herein, a glucose biosensor was developed by anchoring glucose oxidase (GOD) within the polyaniline (PANI)-montmorillonite (MMT)-platinum nanoparticles (PtNPs) nanocomposite through the electrodeposition of PtNPs on the PANI-MMT hybrid composites, which had been prepared on the surface of platinum plate electrode by in situ electrochemical suspension polymerization. Scanning electron spectroscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and amperometry measurements were employed to characterize the morphology and electrochemical properties of the as-prepared biosensor. No current response was monitored from the possible interferents such as glycine (Gly), urea (Urea), L-phenylalanine (L-Phe), ascorbic acid (AA), L-tyrosine (L-Tyr) and D-galactose (D-Gal). The signal intensity towards glucose detection kept almost no change after storage for 40 days, and still remained above 91.7% of original value even after two months. The developed biosensor revealed a quick response to glucose over a wide linear range from 10 mu M to 1.94 mM and a low detection limit of 0.1 mu M. The biosensor was successfully applied for glucose detection in human blood serum. The results demonstrate the possible control of nanocomposite microenvironment by using electrochemical synthesis to obtain molecular level dispersion for immobilizing glucose oxidase, and enhance electron transfer and electrocatalytic effect.