Investigating the effects of two different carbon materials on the sensitivity of an electrochemical impedimetric lectin-based biosensor

Abstract

Carbon materials have proven to be promising materials in electrochemical biosensors. Here, the effect of two different carbon materials on the sensitivity of a label-free electrochemical impedimetric lectin-based biosensor was investigated. Graphene (G) and carbon nanospheres (CN-10) were individually used to fabricate a sensing surface with an incorporated electrodeposition of gold nanoparticles on a glassy carbon electrode. Lectin of Con A was covalently immobilized by a coassembly of 11-mercaptoundecanoic acid and dithiothreitol with carbodiimide chemistry. In a measurement of mannan (as the target model), the change in the interfacial electron transfer resistance of the biosensor was monitored using a redox couple of Fe(CN)63-/4-, and this change was used to compare the effect of the two different carbon materials on the sensitivity of the biosensor. The results showed that G had a better performance than that of CN-10 under the conditions in this study. This work demonstrates that the use of G as an immobilization platform is a promising approach to designing impedimetric lectin-based biosensors with high sensitivity when compared to that of CN-10.