Antifouling electrochemical biosensors based on mussel-inspired poly(norepinephrine) and functional peptides for the detection of extracellular signal-regulated kinase 2 in serum

Abstract

The adsorption of nonspecific biomolecules on sensing surfaces presents a challenge for accurate and sensitive detection of targets in complex biological samples, which significantly restricts the practical application of biosensors. It is therefore crucial to develop sensing devices with antifouling capabilities. Herein, a low fouling electrochemical biosensing platform has been developed that leverage two kinds of antifouling materials. One material employed is a specially designed functional peptide, while the other is inspired by the adhesive properties of mussels, known as poly(noradrenaline) (PNE). Compared with polydopamine, the PNE is more effective in reducing the nonspecific adsorption in serum samples. The biosensor, which was developed using PNE and peptide, demonstrated exceptional resistance to fouling and a broad liner detection range of 10.0 pg·mL⁻¹ - 10.0 µg·mL⁻¹ for the detection of the target extracellular signal-regulated kinase 2 (ERK2), allowing for accurate measurements over a broad range of concentrations, with a limit of detection of 3.97 pg·mL⁻¹. The antifouling biosensor was able to detect target ERK2 in serum without pretreatment, and with satisfying accuracy comparable to the ELISA kit. This approach for the construction of low fouling biosensors using peptides and PNE can be easily extended to develop other sensing systems for various targets analysis in human body fluids.