D-Amino Acid-Based Antifouling Peptides for the Construction of Electrochemical Biosensors Capable of Assaying Proteins in Serum with Enhanced Stability

Key Words:ENZYMATIC STABILITY; ALPHA; SUBSTITUTION; RECOGNITION; STRATEGIES; SEQUENCE; SENSORS; SURFACE

Abstract:The susceptibility of peptides to proteolytic degradation in human serum significantly hindered the potential application of peptide-based antifouling biosensors for long-term assaying of clinical samples. Herein, a robust antifouling biosensor with enhanced stability was constructed based on peptides composed of D-amino acids (D-peptide) with prominent proteolytic resistance. The electrode was electropolymerized with poly(3,4-ehtylenedioxythiophene) and electrodeposited with Au nanoparticles (AuNPs), and the D-peptide was then immobilized onto the AuNPs, and a typical antibody specific for immunoglobulin M (IgM) was immobilized. Because of the effect of D-amino acids, the D-peptide-modified electrode surface showed prominent antifouling capability and high tolerance to enzymatic hydrolysis. Moreover, the D-peptide-modified electrode exhibited much stronger long-term stability, as well as antifouling ability in human serum than the electrode modified with normal peptides. The electrochemical biosensor exhibited a sensitive response to IgM linearly within the range of 100 pg mL(-1 )to 1.0 mu g mL(-1) and a very low detection limit down to 37 pg mL(-1), and it was able to detect IgM in human serum with good accuracy. This work provided a new strategy to develop robust peptide-based biosensors to resist the proteolytic degradation for practical application in complex clinical samples.

Volume:7

Issue:6

Translation or Not:no