SECM for Studying the Immobilization and Repartition of a Redox Anti‐tetracycline Aptamer on Screen‐printed Carbon Electrodes

Abstract

Scanning electrochemical microscopy (SECM) is discussed as a versatile tool to provide a unique approach of localized electrochemical information in the context of biosensing research. The step‐by‐step immobilization of DNA aptamer with intrinsic redox activity on screen‐printed carbon electrode (SPCE) was successfully monitored using SECM imaging tool. Control experiments were performed with a non‐electroactive aptamer. After immobilization of these aptamers, SECM images showed the repartition of the electroactive anti‐tetracycline aptamer when comparing with images produced for control and for all modification steps of SPCE. The possibility of tetracycline detection was also proved by causing a decrease in recorded current.

The Role of Aryldiazonium Chemistry in Designing Electrochemical Aptasensors for the Detection of Food Contaminants

“…Scanning electrochemical microscopy (SECM) has also been recently employed as a detection technique for electrochemical aptasensors [ 59 ]. In one published study, a specific TET aptamer [ 60 ] was immobilized by carbodiimide-mediated coupling onto a carboxyphenyl-modified SPCE by diazonium chemistry.…”

“…This assessment was made by imaging the intense spots that appeared on the scanned area, consistent with the increase in the oxidation current of the aptamer recorded at the UME tip. Following TET binding, a substantial decrease in current was evidenced, a typical feature of the signal-off sensors [ 59 ].…”