Figure 3.

(A) Illustration of the electrochemical setup under electrolyte solution. Dotted circle depicts the digital image of Au-PCB working electrode and the process of glucose oxidase modification at two different stages, ie, Au-PCB-GO and Au-PCB-FGO biosensor platform, respectively. (B) Enzymatic reaction at the electrode interface and its respective cyclic voltammogram.

Abbreviations: Ag/AgCl, silver/silver chloride; RE, reference electrode; Pt, platinum; CE, counter electrode; Au-PCB, gold printed circuit board electrode; WE, working electrode; Au-PCB-GO, gold printed circuit board electrode modified with graphene oxide; Au-PCB-FGO, gold printed circuit board electrode modified with functionalized graphene oxide; GOx, glucose oxidase; Ag@SiO₂-PEG, silver-silica coated with polyethylene glycol; FGO, functionalized graphene oxide; GO, graphene oxide.