Aptamer versus antibody as probes for the impedimetric biosensor for human epidermal growth factor receptor.

In the present work, the performance of aptamer and antibody bioreceptors for the detection of the human epidermal growth factor receptor (HER2) cancer biomarker on a glassy carbon electrode is reported. The carboxylic acid group rich graphene quantum dots (GQDs) modified with gold nanoparticles and a porphyrin binuclear framework (CoP-BNF) were used to modify the glassy carbon electrode. The aptamer and antibody were both amine functionalized and attached to GQDs and CoP-BNF through an amide bond. The designed immunosensors and aptasensors in this work were characterized using electrochemical impedance spectroscopy. The aptasensors, compared to the immunosensors gave better limit of detection values. The aptasensor outperforms the immunosensor in terms of its reusability and storability, while the immunosensor could not be regenerated for subsequent experiments. The potential applicability of all sensors in this work was also investigated, by detection of HER2 in spiked human serum with acceptable results.