ABSTRACT
The development of an Aptamer based biosensor for the selective detection of human epidermal growth factor receptor 2 (HER2) with high sensitivity and specificity was achieved. A screen-printed carbon electrode was used in the scope of this work. The HER2 Aptamer was immobilized via electrostatic adsorption on the surface of a screen-printed electrode, which was modified with Au Nanoparticles (~ 20 nm diameter) to support the Aptamer immobilization. The Aptasensor was extensively investigated using Cyclic voltammetry, Differential pulse voltammetry, Electrochemical impedance spectroscopy, Fourier transform infrared spectroscopy and Atomic force microscopy. The Aptasensor exhibits a fast response with a binding time of only 5 min and shows a log-linear response over a wide concentration range of 0.001-100 ng/mL. Moreover, it has high sensitivity and enhanced detection limit reaching 52.85 µA/ng/mL, and 0.001 ng/mL, respectively, with a relative standard deviation < 5%. The Aptasensor selectivity was studied by using different interfering substances, and the results demonstrate that the Aptasensor is efficient for the detection of HER2 with approximately 8% extent of the interference.
