Nanomolar detection of dopamine in the presence of ascorbic acid at β-cyclodextrin/graphene nanocomposite platform

Nanocomposite of β-cyclodextrin and graphene sheet (β-CD/GS) was successfully prepared, which exhibited high stability in aqueous solution. When used in electrochemical detection of dopamine, the β-CD/GS modified carbon electrode showed low detection limit, broad linear range, along with good ability to suppress the background current from large excess ascorbic acid. The electrochemical reaction of dopamine on the β-CD/GS showed a mass diffusion-controlled process, which was different from the adsorption-controlled process on the unmodified graphene sheet.