Electrochemical sensing interfaces based on hierarchically architectured zwitterionic peptides for ultralow fouling detection of alpha fetoprotein in serum

Herein, an electrochemical sensing platform based on zwitterionic peptide with a hierarchical structure was constructed for ultralow fouling and highly sensitive protein quantification. Through the combination of CPPPPEKEKEKEK and CPPPPEKEKEK peptides, hierarchical antifouling peptide brushes were formed and exhibited excellent antifouling property, which can be further modified with alpha fetoprotein (AFP) aptamer to achieve highly sensitive detection of AFP. The hierarchical peptide brush-based sensor system achieved an AFP quantification range from 1.0 fg mL(-1) to 1.0 ng mL(-1), with a very low limit of detection as low as 0.59 fg mL(-1). In addition, due to the superior antifouling property of the newly designed hierarchical peptide brushes, the electrochemical biosensor supported the quantification of AFP in solutions with a high concentration of nonspecific proteins without sacrifice in sensitivity. It is worth noting that the constructed antifouling biosensor ensured quantitative recruitment of AFP in clinical serum samples with acceptable accuracy when compared with the commonly used method in the hospital. The strategy of constructing sensing interfaces based on designed hierarchical peptide brushes provided an effective way to develop biosensors with both excellent antifouling capability and high sensitivity. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

An electrochemical sensing platform based on a hierarchical structure of zwitterionic peptides was developed for highly sensitive protein quantification with ultra-low fouling properties. The hierarchical peptide brush-based sensor system achieved a wide range of AFP quantification and a very low limit of detection, demonstrating excellent antifouling capabilities. The strategy of constructing sensing interfaces using designed hierarchical peptide brushes offers an effective way to develop biosensors with both excellent antifouling capability and high sensitivity.