Controlled diazonium electrodeposition towards a biosensor for C-reactive protein

Abstract

Electrografting of aryldiazonium species is useful for linkage between electrochemical transducer surface and biosensor recognition elements. However, the process proceeds uncontrollably to form branched/multilayer growth. This paper reports harnessing steric hindrance for controlled growth of aryldiazonium coupling agent during electrografting to screen-printed carbon electrode surface, which was subsequently used for linkage of CRP recognition elements to form a biosensor with greater sensitivity (32.0 ± 0.5 μA/(ng/mL) than that formed by way of uncontrolled growth (26.6. ± 5.3 μA/(ng/mL) across a highly sensitive operating range of 0.01–10 ng/mL. To the best of our knowledge, this is the first report of this approach demonstrated as a route for biosensor fabrication. This finding suggests the approach can be exploited in immunosensor assays.

Keywords

• Aryldiazonium salt
• Aryldiazonium grafting
• C-reactive protein
• Electrochemical biosensor