One-step synthesis of silver nanoparticles/carbon nanotubes/chitosan film and its application in glucose biosensor

One-step synthesis of silver nanoparticles/carbon nanotubes/chitosan film (Ag/CNT/Ch) was firstly proposed as a novel immobilization matrix for the enzymes to fabricate sensitive glucose biosensor. The biosensor was prepared by embedding horseradish peroxidase (HRP) and glucose oxidase (GOD) in Ag/CNT/Ch hybrid films based on layer by layer technique. The electron mediator, o-phenylenediamine (OPD), was also co-immobilized with HRP in the inner layer on the surface of an indium tin oxide (ITO) electrode. Hydrogen peroxide produced by the GOD catalytic oxidation of glucose was then detected by OPD in the presence of HRP. Under the optimized experimental conditions, the resulting biosensor could detect glucose in a linear range from 0.5 to 50 μM with a detection limit of 0.1 μM at a signal-to-noise ratio of 3. The sensitivity was calculated as 135.9 μA mM−1. The proposed biosensor offered sensitive amperometric responses to glucose based on the Ag/CNT/Ch films.