Electrochemical modification at multiwalled carbon nanotube electrodes with Azure A for FAD- glucose dehydrogenase wiring: structural optimization to enhance catalytic activity and stability

Abstract Electrochemical grafting is a suitable technology for fabricating electrode surfaces with new chemical functionalities whilst maintaining the bulk properties of electrode, and electrochemical amine oxidation diazonium salt reduction are two widely used techniques to achieve this end. Herein, we report reductive Azure A onto multiwalled carbon nanotube (MWCNT) electrodes efficient wiring flavin adenine dinucleotide (FAD) dependent glucose dehydrogenase. The formed in situ subsequently grafted surface through reduction. formal potential resultant Azure-A-modified shifted −0.05 V vs. Ag/AgCl upon radical coupling MWCNT electrode. Electron transfer from FAD buried protein shell via was then observed presence buffer solution. This study focused on important effect CNT mass loading Azure-A as well bioelectrocatalytic activity storage stability. three-dimensional porous structure determined be favorable immobilization dehydrogenase electron functionalities. optimized 300 µ g CNT-loaded modified glassy (3 mm diameter) retains its initial 3 d 25% after 10 d. Furthermore, show that stably immobilized MWCNTs 1 month; therefore, limiting stability factor enzyme leaching and/or deactivation.