Electrochemical detection of HER2 using single stranded DNA aptamer modified gold nanoparticles electrode

In the present study, a novel impedance aptasensor was developed by immobilizing HER2 (human epidermal growth factor receptor 2)-specific single stranded DNA aptamer onto the monolayer of 3-mercaptopropionic acid self-assembled on gold nanoparticles electrode. The efficiency of each electrode modification step and the performance of thus constructed aptasenor were assessed by impedance spectroscopy. The impedance response of the aptasensor showed a proportional relationship with the concentrations of HER2 ranged from 10^-5 to 10² ng/mL. The aptasensor showed fast HER2 detection with negligible cross reactivity to various compounds likely to exist in human serum samples (e.g. glucose, IgG, DNA and RNA), indicative of excellent sensitivity and specificity of the aptasensor. The aptasensor could be regenerated by a simple pH-shift method. Considering these advantages of the developed aptasensor, it could provide a good potential sensing platform for non-invasive early detection of breast cancer biomarkers.