Dehydrogenase-Based Reagentless Biosensors: Electrochemically Assisted Deposition of Sol-Gel Thin Films on Functionalized Carbon Nanotubes
Abstract
Multiwalled carbon nanotubes (MWCNT) have been functionalized, for the electrocatalytic detection of NADH, by microwave treatment, electrochemical deposition of poly(methylene green) or wrapping with an Os‐complex modified polymer. Sol‐gel thin films have been then electrodeposited on the carbon nanotube layers for co‐immobilization of D‐sorbitol dehydrogenase and diaphorase when necessary and NAD+ via covalent linkage using glycidoxypropyltrimethoxysilane. The comparison of these systems shows that the electrodeposited sol‐gel matrix can significantly affect the operational behavior of functionalized MWCNT. Only MWCNT wrapped with the Os‐complex modified polymer and covered with a sol‐gel biocomposite allowed the electrochemical detection of D‐sorbitol in a reagentless configuration.