An electrochemical biosensor for HER2 detection in complex biological media based on two antifouling materials of designed recognizing peptide and PEG.

A simple tactic for electrochemical determination of a typical biomarker for breast cancer, human epidermal growth factor receptor 2 (HER2), was presented via the construction of a low fouling sensing interface functionalized with polyethylene glycol (PEG) and peptide. The HER2 biosensor was developed based on an electrode modified by the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) and Au nanoparticles (AuNPs) as the sensing substrate, and followed by the immobilization of an antifouling PEG and a peptide with both recognizing and antifouling properties. Thanks to the combined antifouling effect of the PEG and peptide, and the specific recognizing ability of the peptide to the target HER2, the developed electrochemical biosensor exhibited strong antifouling performances in complex biofluids, such as human blood and serum, and it was capable of assaying target HER2 within a very wide linear range (1.0 pg mL-1 to 1.0 μg mL-1), with an ultralow limit of detection (0.44 pg mL-1). The combination of two kinds of antifouling biomaterials (PEG and peptide) offered an effective strategy for the development of low fouling sensing platforms suitable for practical assay in complex biotic environments.