Amperometric glucose biosensor based on a triangular silver nanoprisms/chitosan composite film as immobilization matrix

We report on the utilization of triangular silver nanoprisms (AgTNPs) to create a highly responsive glucose biosensor. Glucose oxidase (GOD) was simply mixed with AgTNPs and cross-linked on the Pt electrode with chitosan (CHIT) medium by glutaraldehyde. Circular dichroism (CD) and UV-spectrum results show that the activity of GOD was preserved after conjugating with AgTNPs. The current response of modified electrode is 16 times higher than that without AgTNPs. The biosensor showed high sensitivity (67.17 mu A cm(-2) mM(-1)), low detection limit (1 x 10(-6) M), good storage stability, and high affinity to glucose (K-M = 3.84 mM). A linear calibration plot was obtained in the wide concentration range from 3 x 10(-6) to 3 x 10(-3) M. The excellent performance of the biosensor is attributed to large surface-to-volume ratio and high conductivity of AgTNPs, and good biocompatibility of CHIT, which enhances the enzyme absorption and promotes electron transfer between redox enzymes and the surface of electrodes. (C) 2010 Elsevier B.V. All rights reserved.