Low fouling electrochemical biosensors based on designed Y-shaped peptides with antifouling and recognizing branches for the detection of IgG in human serum.

The nonspecific adsorption and accumulation of biomolecules on electrode interfaces remains a challenge for sensitive and accurate detection of disease markers in complex biological media, and it is highly desired to develop antifouling biosensors capable of assaying targets in complicated real liquids. Herein, an efficient and simple antifouling biosensor was constructed based on a self-designed Y-shaped peptide. The Y-shaped peptide was designed with two branches: one branch with the peptide sequence of EKEKEKE for antifouling, and the other branch with the peptide sequence of HWRGWVA for recognizing of human IgG. Under optimized experimental conditions, electrodes modified with Y-shaped peptides exhibited excellent antifouling and electrochemical sensing performances. The developed biosensor was able to effectively resist biofouling in various protein solutions and even serum samples, and the linear range of the biosensor for human IgG detection was from 100 pg mL-1 to 10 μg mL-1, with a relatively low limit of detection of 32 pg mL-1 (S/N = 3). The antifouling biosensor possesses the capability of assaying human IgG in real serum samples, and this strategy of developing low fouling biosensors based on Y-shaped peptides can be readily expanded to the construction of other biosensing systems for different targets.