Antifouling zwitterionic peptide hydrogel based electrochemical biosensor for reliable detection of prostate specific antigen in human serum
Graphical abstract
An antifouling electrochemical biosensor based on designed zwitterionic peptide hydrogel was constructed for the detection of cancer biomarker PSA in real complex serum sample.
Introduction
In the early diagnosis, prostate specific antigen (PSA), as a cancer biomarker, can be used for primary screening for prostate cancer [1,2]. The concentration of PSA is below 4.0 ng mL−1 in serum of normal human, and people are at increased risk of being diagnosed with prostate cancer when the concentration of PSA exceeds the threshold [3]. At present, the commonly utilized methods for the specific determination of PSA include surface plasmon resonance technique [4], electrochemical detection [5], electrochemiluminescence analysis [6], amperometric immunoassay [7] and so on. Among them, the electrochemical analysis has drawn substantial attention owing to its sensitivity, convenience, and low cost [[8], [9], [10]]. Nevertheless, the absorption of an enormous number of nonspecific proteins and cells on the interface of electrochemical sensors poses a serious biofouling problem when those biosensors performed in real complex samples [11]. Therefore, it is necessary to explore biosensors with antifouling capability for target detection in complex biological environments.
To date, various materials have been applied to prevent nonspecific adsorption of proteins and other biomolecules onto the sensing surfaces of electrochemical devices [[12], [13], [14]]. Typically, poly (ethylene glycol) (PEG) and its derivatives are extensively adopted for the construction of antifouling surfaces [15]. However, PEG is vulnerable to oxidative degradation, which affect its long-term practical application [16]. Zwitterionic polymers can combine with water molecules to form a tightly bound hydration layer, which possess resistance ability of protein adsorption [17]. Furthermore, zwitterionic polymers simultaneously contain the same account of cationic and negative groups and can be electrically neutral [18], and the charges can attract water molecules to enhance their hydration [19]. For example, Liu et al. have proved that the zwitterionic polymers formed brushes exhibited stronger hydration than the PEG brushes [20].
Zwitterionic peptides, composed of amino acid residues with positive and negative charges, are similar to zwitterionic polymers and can be neutral in charge [21]. Additionally, zwitterionic peptides have excellent biocompatibility compared with other zwitterionic polymers. Consequently, peptides with different composition and chain length consist of natural and synthetic amino acids can form diverse sequences of peptides with various antifouling capabilities [22,23]. For example, Chen's group has proved that EK amino acid residues presented by alternating or mixed charges were effective for the construction of almost nonfouling peptides [24]. Ye et al. have reported that the p-EK peptide self-assembled to thiolated hyaluronic acid (HA)-modified gold substrate, which exhibited excellent antifouling performance [25].
Hydrogels have been widely investigated in biosensor [26], wound healing [27], tissue engineering [28], drug delivery [29], antimicrobial materials [30] and implantable medical devices [31] due to their advantages including favorable hydrophilicity and biocompatibility. Peptide hydrogels prepared by self-assembly are formed into stable structures through various interactions, such as the hydrogen bond, electrostatic interaction, π-π stacking, and hydrophobic and hydrophilic interactions [32,33]. In addition, peptide hydrogel with a high water content can facilitate to form a hydration layer that effectively avoids the adhesion of nonspecific biomolecules [34]. Therefore, they are potentially suitable for the construction of electrochemical biosensors with antifouling abilities [35,36]. Nevertheless, little related work has been done to explore the application of zwitterionic peptide hydrogel in antifouling sensors.
Herein, the zwitterionic peptide hydrogel with a sequence of CFEFKFC was successfully prepared and adopted for the development of low fouling biosensors. Peptide hydrogels and the conducting polymer PEDOT were modified onto the electrode surface to fabricate the antifouling electrochemical biosensor. As shown in Scheme 1, the electrode was sequentially modified with PEDOT and gold nanoparticles (AuNPs) by electrodeposition, and then the zwitterionic peptide hydrogel with terminal cysteine (C) thiol groups were attached to the AuNPs via the Au–S bonds. After the further immobilization of anti-PSA antibodies, the antifouling biosensor for PSA detection in complex biological environments was developed.
Section snippets
Reagents
The peptide (CFEFKFC) designed by our group was synthesized and purified by the Bankpeptide Biological Technology Co., Ltd. (Hefei, China). Prostate specific antigen (PSA), horseradish peroxidase (HRP)-conjugated immunoglobulin G (IgG), anti-PSA antibody (Ab) and PSA ELISA kit were obtained from Sangon Biotech Co., Ltd., (Shanghai, China). 3,4-ethylenedioxythiophene (EDOT), chloroauric acid (HAuCl4) were obtained from Aladdin Reagents (Shanghai, China). Poly (sodium 4-styrenesulfonate) (PSS),
Characterization of the CFEFKFC peptide hydrogels
The photograph of an inverted vial containing the prepared peptide hydrogel was shown in Fig. 1A. Gels remained intact under gravity and no fluid was observed in the bottle, proving the successful preparation of the CFEFKFC-based peptide hydrogel. Fig. 1B depicted the rheological measurement of CFEFKFC-based hydrogel. The storage modulus was obviously much higher than the loss modulus, testifying the viscoelastic property of solid-like hydrogels. The microscopic structure was visualized by TEM
Conclusion
In conclusion, we have developed an electrochemical biosensor with excellent antifouling capability based on the self-assembled zwitterionic peptide hydrogels. The novelty designed peptide hydrogel with neutral charged exhibit strong hydrophilicity and biocompatibility. Moreover, zwitterionic peptide hydrogels were combined with the conducting polymer PEDOT to construct electrochemical biosensors with exceptional antifouling properties for precise detection of the cancer biomarker PSA in
CRediT authorship contribution statement
Qiushu Du: Conceptualization, Methodology, Investigation, Writing – original draft, Visualization, Data curation. Wenqi Wang: Conceptualization, Data curation, Writing – review & editing. Xianghua Zeng: Visualization, Writing – review & editing. Xiliang Luo: Conceptualization, Methodology, Writing – review & editing, Visualization, Supervision, Funding acquisition.
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
The authors acknowledge financial support from the National Natural Science Foundation of China (22174082, 21974075), the Key Research and Development Program of Shandong Province (2021ZDSYS30) and the Science and Technology Benefiting the People Project of Qingdao (20-3-4-53-nsh).
References (36)
- et al.
Prostate-specific antigen immunosensing based on mixed self-assembled monolayers, camel antibodies and colloidal gold enhanced sandwich assays
Biosens. Bioelectron.
(2005) - et al.
Microcontact imprinting based surface plasmon resonance (SPR) biosensor for real-time and ultrasensitive detection of prostate specific antigen (PSA) from clinical samples
Sensor. Actuator. B Chem.
(2016) - et al.
Highly sensitive label-free amperometric immunoassay of prostate specific antigen using hollow dendritic AuPtAg alloyed nanocrystals
Biosens. Bioelectron.
(2018) - et al.
A highly sensitive biosensor for tumor maker alpha fetoprotein based on poly(ethylene glycol) doped conducting polymer PEDOT
Biosens. Bioelectron.
(2016) - et al.
Electrochemical sensing interfaces based on hierarchically architectured zwitterionic peptides for ultralow fouling detection of alpha fetoprotein in serum
Anal. Chim. Acta
(2021) - et al.
An ultrasensitive biosensor based on three-dimensional nanoporous conducting polymer decorated with gold nanoparticles for microRNA detection
Microchem. J.
(2021) - et al.
Anti-biofouling Ti3C2TX MXene-holey graphene modified electrode for dopamine sensing in complex biological fluids
Talanta
(2022) - et al.
Constructing zwitterionic polymer brush layer to enhance gravity-driven membrane performance by governing biofilm formation
Water Res.
(2020) - et al.
Designed zwitterionic peptide combined with sacrificial Fe-MOF for low fouling and highly sensitive electrochemical detection of T4 polynucleotide kinase
Sensor. Actuator. B Chem.
(2020) - et al.
Structures and antifouling properties of self-assembled zwitterionic peptide monolayers: effects of peptide charge distributions and divalent cations
Biomacromolecules
(2020)
Ultra-low fouling peptide surfaces derived from natural amino acids
Biomaterials
Recent advances in self-assembled peptides: implications for targeted drug delivery and vaccine engineering
Adv. Drug Deliv. Rev.
Development of disulfide bond crosslinked antimicrobial peptide hydrogel
Colloids Surf. A Physicochem. Eng. Asp.
Fabrication of biocompatible hydrogel coatings for implantable medical devices using Fenton-type reaction
Mater. Sci. Eng. C
An electrochemical peptide cleavage-based biosensor for prostate specific antigen detection via host-guest interaction between ferrocene and β-cyclodextrin
Chem. Commun.
Prevalence of prostate cancer among men with a prostate-specific antigen level <= 4.0 ng per milliliter
N. Engl. J. Med.
Electrochemical assays for determination of H2O2 and prostate-specific antigen based on a nanocomposite consisting of CeO2 nanoparticle-decorated MnO2 nanospheres
Microchim. Acta
Bidirectional electrochemiluminescence color switch: an application in detecting multimarkers of prostate cancer
Anal. Chem.
Cited by (17)
A comprehensive review on the inherent and enhanced antifouling mechanisms of hydrogels and their applications
2024, International Journal of Biological MacromoleculesAn antifouling coating that enables electrochemical biosensing of MecA gene in complex samples
2024, Chemical Engineering JournalMultifunctional DNA scaffold mediated gap plasmon resonance: Application to sensitive PD-L1 sensor
2024, Biosensors and BioelectronicsThe application of computer simulation in biomedical hydrogels research: A review
2024, Journal of Molecular LiquidsL-Cysteine functionalized halloysite nanotubes/PVDF ultrafiltration membrane for improving anti-fouling performance
2023, Journal of Environmental Chemical Engineering