Sensitive and Selective Electrochemical Glucose Biosensor Based on a Carbon Nanotube Electronic Film

This work presents a non-destructive and straightforward approach to assemble a large-scale conductive electronic film made of a pre-treated single-walled carbon nanotube (SWCNT) solution. For effective electron transfer between the immobilized enzyme and SWCNT electronic film, we optimized the pre-treatment step of SWCNT with p-terphenyl-4,4''-dithiol and dithiothreitol. Glucose oxidase (GOx, a model enzyme in this study) was immobilized on the SWCNT electronic film follow-ing the positively charged polyelectrolyte layer deposition. The glucose detection was realized through effective electron transfer between the immobilized GOx and SWCNT electronic film at the negative potential value (-0.45 V vs. Ag/AgCl). The SWCNT electronic film-based glucose biosensor exhibited a sensitivity of 98 µA/mM⋅cm². In addition, the SWCNT electronic film biosensor showed the excellent selectivity (less than 4 % change) against a variety of redox-active interfering sub-stances, such as ascorbic acid, uric acid, dopamine, and acetaminophen, by avoiding co-oxidation of the interfering substances at the negative potential value.