Highly sensitive ochratoxin A impedimetric aptasensor based on the immobilization of azido-aptamer onto electrografted binary film via click chemistry

The aptamer immbolization onto organized mixed layers of diazonium salts via click chemistry was explored. The immobilized aptamer was employed in the fabrication of a highly sensitive and reusable electrochemical impedimetric aptasensor for the detection of ochratoxin A (OTA). The screen-printed carbon electrodes (SPCEs) were first modified by electrografting of a protected 4-((trimethylsilyl) ethynyl) benzene (TMSi-Eth-Ar) layer followed by a second one of p-nitrobenzene (p-NO2-Ar) by means of electrochemical