Adsorption and Electrooxidation of DNA at Glassy Carbon Electrodes Modified with Multiwall Carbon Nanotubes Dispersed in Glucose Oxidase

We are proposing for the first time the successful immobilization of DNA at glassy carbon electrodes (GCE) modified with carbon nanotubes (CNT) dispersed in glucose oxidase (GOx) (GCE/CNT-GOx) either by direct adsorption or by layer-by-layer self-assembling using polydiallyldimethylamine (PDDA). The presence of GOx allows an efficient dispersion of CNT and gives a most favorable environment that promotes the adsorption and makes possible a more sensitive electrooxidation of DNA. The PDDA incorporated in the self-assembled architecture largely facilitates the adsorption and electrooxidation of dsDNA and the adsorbed layer can be successfully used for evaluating the interaction of DNA with methylene blue.