Surface Modification of Thermoplastic Electrodes for Biosensing Applications via Copper-Catalyzed Click Chemistry

Cu(I)-catalyzed 1,3-dipolar cycloaddition (CuAAC), also known as click chemistry, has been demonstrated to be highly robust while providing versatile surface chemistry. One specific application is biosensor fabrication. Recently, we developed thermoplastic electrodes (TPEs) as an alternative to traditional carbon composite electrodes in terms of cost, performance, and robustness. However, their applications in biosensing are currently limited due to a lack of facile methods for electrode modification. Here, we demonstrate the feasibility of using CuAAC following the diazonium grafting of TPEs to take advantage of two powerful technologies for developing a customizable and versatile biosensing platform. After a stepwise characterization of the electrode modification procedures was performed, electrodes were modified with model affinity reagents. Streptavidin and streptavidin-conjugated IgG antibodies were successfully immobilized on the TPE surface, as confirmed by electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy.