Heterophase-Structured Cobalt Hydroxide on Partly Reduced Graphene Oxide for Enhanced Dopamine Biosensing

A hetero-phase structure of cobalt hydroxide [alpha/beta-Co(OH)(2)] in situ formed with the partly reduced graphene oxide [Co(OH)(2)/PRGO] has been fabricated by a coprecipitation method. Depending on the interactions (nucleation, bonding with oxygen-rich groups, and partial conversion of GO into rGO) provided by GO, cobalt ions utilized the interactions under alkaline conditions provided by 2-methylimidazole to form hetero-phase alpha/beta-Co(OH)(2) and maintain the unstable-structure [alpha-Co(OH)(2)]. Beneficial to the large electrochemical active surface, rich redox active sites, and electronic transfer capability derived from hetero-phase structure [alpha/beta-Co(OH)(2)] and the partly reduced graphene oxide, the Co(OH)(2)/PRGO has an extraordinary detection performance of DA: a multi-section continuous detection range (0.1 nM to 450 mu M), a ultra-low limit of detection (0.078 nM, S/N = 3), and a strong anti-interference ability, coupled with an application potential in biological foods (pork) and in the body environment (serum).