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

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 μg 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.

Electrochemical Immunosensors Based on Zinc Oxide Nanorods for Detection of Antibodies Against SARS-CoV-2 Spike Protein in Convalescent and Vaccinated Individuals

“…XPS analysis of ZnO electrodes revealed the presence of nitrogen on the surface after functionalization, indicating successful spike protein attachment ( Figure S3 ). 89 − 91 Furthermore, it is possible to observe an increase in N 1s peak with the incubation of the antibodies anti-SARS-CoV-2 present in human samples (FTO-ZnONRs/spike/Gly/+serum electrode), revealing the binding of antibodies to the electrode surface ( Figure S3A ). Figure S3B shows the high-resolution spectra for the FTO-ZnONR electrode.…”

pH-Responsive Intelligent Antibacterial Coatings Based on 2D-COF for Controlled Release of Capsaicin

“…23,24 However, it still faces the following challenges: the excessive release of traditional antifouling agents will cause the problem of short service life of the coating. 25,26 At present, the main methods of intelligently controlling the release of antifouling agents are pH response, 24 enzyme response, 27 and temperature response. 28 Up to now, a variety of nanomaterials with good controlled-release properties have been reported, including poly(vinyl alcohol) microspheres in a silk sericin-based hydrogel, 29 composite films with an adjustable number of layers using sodium alginate (SA), chitosan (CS), and activated charcoal (AC), 30 microcrystals, 31 polyvinyl alcohol/chitosan microspheres, 32 and a selenium-rich tea set.…”

“…At present, the main methods of intelligently controlling the release of antifouling agents are pH response, enzyme response, and temperature response . Up to now, a variety of nanomaterials with good controlled-release properties have been reported, including poly­(vinyl alcohol) microspheres in a silk sericin-based hydrogel, composite films with an adjustable number of layers using sodium alginate (SA), chitosan (CS), and activated charcoal (AC), microcrystals, polyvinyl alcohol/chitosan microspheres, and a selenium-rich tea set. , Chitosan (CS) has antibacterial properties due to the interaction between its positively charged amino group and the negatively charged cell membrane of bacteria. , The nanocapsules made from CS exhibit typical pH response characteristics due to the large number of amino groups contained in the side chain. , In addition, the intelligent delivery of fungicides can be realized by the modification of chitosan. , Our research group has developed a capsaicin@chitosan (CAP@CS) microcapsule with pH response performance, which can realize the intelligent controlled release of the natural bactericide CAP, which plays an effective sterilization and antifouling role. , However, its dispersion is limited.…”

A Wearable Electrochemical Sensor Based on Anti-Fouling and Self-Healing Polypeptide Complex Hydrogels for Sweat Monitoring

“…To address these challenges and bridge the gap between laboratory testing and in situ monitoring, a polypeptide complex hydrogel (AuNPs/MoS 2 /Pep hydrogel) as a soft electronic skin was created. Remarkably, the precise control of −COOH and −NH 2 endowed the peptide with extreme hydrophilicity and electric neutrality, forming an anti-fouling membrane on the electrochemical sensor surface to alleviate nonspecific adhesion. , Moreover, regulation of the polypeptide structure with a D-type structure contributed to accomplishing long-time applications. , Furthermore, MoS 2 /Pep hydrogels could be conferred specific self-healing modes by an unbroken physical π–π stacking force between naphthalene-modified peptides (Nap-peptide) and MoS 2 . AuNPs/MoS 2 contributed selective and sensitive sensing properties of UA and AA in sweat in situ.…”

“…22,23 Moreover, regulation of the polypeptide structure with a D-type structure contributed to accomplishing long-time applications. 24,25 Furthermore, MoS 2 /Pep hydrogels could be conferred specific self-healing modes by an unbroken physical π−π stacking force between naphthalene-modified peptides (Nap-peptide) and MoS 2 . AuNPs/MoS 2 contributed selective and sensitive sensing properties of UA and AA in sweat in situ.…”