Improved characters of screen-printed carbon paste electrodes modified by hydrophilic nano-SiO2

In this study, K3Fe (CN6) acted as electron transport reagent, and glucose oxidase was immobilized in the multiple membrane matrix consisting of polymer and hydrophilic nano-SiO2 on screen-printed carbon paste electrodes. In this way a glucose biosensor modified with hydrophilic nano-SiO2 and polymer was completed. The experimental results showed that the sensitivity of carbon paste electrodes modified with nano-SiO2 was 2.6 times of unmodified, Measurable linear range is 1.1-33.3 mmol/L. To different concentration glucose, the RSDs were less than 5% with a better repeatability and stability. The experiment results turned out that the membrane of nano-SiO2 doping had a good hydration, nano-SiO2 could increase the quantity of immobilized enzyme, so the kinetic process of enzymatic reaction was improved greatly with potential applieation.