Fabrication of nanocomposites based on graphene oxide/carbon nanotube for electrochemical sensing of glucose and dopamine

The real-time monitoring of key metabolites, notably glucose and dopamine, has emerged as a critical imperative for advancing human healthcare. Biosensors, especially for electrochemical detection, present a cost-effective and practical approach to achieve rapid and efficient molecular detection. This study presented a strategic advancement in electrochemical sensing technology through the rational design of a hybrid nanocomposite as substrate. By integrating multifunctional graphene oxide (GO) nanosheets with carbon nanotubes (CNT), we engineered a platform for the immobilization and stabilization of gold nanoparticles (AuNPs), yielding a highly dispersed and electroactive Au@SH-GO-PEG/CNT nanocomposite. Concretely, in Au@SH-GO-PEG/CNT dispersion, the compatible polymer (PEG) was conjugated on GO sheets to ensure colloidal stability and uniform dispersion, thiol groups were introduced into GO sheets to anchor AuNPs, and CNT was integrated into GO for enhancement of electrochemical activity. In subsequent electrochemical detection of glucose and dopamine, it was informed that GCE/Au@SH-GO-PEG/CNT could serve as a promising substrate for a sensitive and stable electrochemical sensor, on account of systemic CV curves and corresponding amperometric responses. Thus, it is reasonable to anticipate that this rationally designed GO-CNT hybrid nanocomposite can act as an effective platform for stabilizing AuNPs while preserving their inherent properties. The strategic integration of CNT within GO could synergistically amplify the electrochemical activity of the AuNPs/GO system.