Events The 4th International Electronic Conference on Biosensors

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Published

This submission belongs to the session F. Nanomaterials and Smart Surfaces in Biosensors of the event The 4th International Electronic Conference on Biosensors

Published date

28 May, 2024

Academic Editor

Michael Thompson

Citation

Daniil Chumakov, Stella Evstigneeva, Valeria Igolkina, Boris Khlebtsov, Biofunctionalization of CTAC-stabilized gold petal-like gap-enhanced Raman tags with monoclonal antibodies via a polydopamine coating for the detection of the SARS-CoV-2 spike protein, in Proceedings of The 4th International Electronic Conference on Biosensors, 20 May–22 May 2024, MDPI: Basel, Switzerland

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Biofunctionalization of CTAC-stabilized gold petal-like gap-enhanced Raman tags with monoclonal antibodies via a polydopamine coating for the detection of the SARS-CoV-2 spike protein

Daniil Chumakov ¹

Stella Evstigneeva ¹

Valeria Igolkina ²

Boris Khlebtsov ³

1. Institute of Biochemistry and Physiology of Plants and Microorganisms – Subdivision of the Federal State Budgetary Research Institution Saratov Federal Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 410049, Saratov, Russia, Russia

2. Saratov State Medical University of V. I. Razumovsky, Ministry of Health of the Russian Federation, 410012 Saratov, Russia, Russia

3. Institute of Biochemistry and Physiology of Plants and Microorganisms – Subdivision of the Federal State Budgetary Research Institution Saratov Federal Scientific Centre of the Russian Academy of Sciences (IBPPM RAS), 410049, Saratov, Russia, Russia

Abstract

Introduction

Incorporating SERS tags into clinical diagnostics holds the potential to increase the sensitivity of diagnostic techniques. Gold petal-like gap-enhanced Raman tags (pGERTs) exhibit an exceptionally high Raman signal. However, the complexity of pGERT functionalization with recognition molecules limits their application in immunoassays. In this study, we have developed a novel method for biofunctionalization of pGERTs with monoclonal antibodies specific to the SARS-CoV-2 spike protein, employing controlled assembly of polydopamine (PDA) on the nanoparticle surface.

Methods

CTAC-coated pGERTs, containing 4-nitrobenzenethiol (4-NBT), were synthesized and characterized. Prior to PDA layer deposition, pGERTs were pre-functionalized with various polymers. Conjugation of PDA-coated pGERTs with monoclonal antibodies specific for S-protein was conducted, and the success of conjugation was confirmed via a dot-immunoassay.

Results

It was demonstrated that replacing CTAC with polystyrene sulfonate on the surface of 60 nm pGERTs allows for controlled PDA growth, resulting in a 3-4 nm-thick PDA layer. Spectrophotometry revealed a broadening of the absorption spectrum and a 4 nm red-shift in the absorption peak of PDA-coated pGERTs. The SERS spectrum of these particles exhibited all characteristic bands of 4-NBT. A dot-immunoassay confirmed the selective staining of the S-protein at varying concentrations (1, 10, 50 μg/mL) by the resulting conjugates.

Conclusions

We have developed a method for the biofunctionalization of pGERTs with monoclonal antibodies specific to the S-protein. The obtained results offer potential applications in the development of SERS-based immunoassay systems.

Acknowledgements

This research was supported by the Russian Science Foundation, grant number № 23-24-00246 (https://rscf.ru/project/23-24-00246/).

Keywords

Gap-enhanced Raman tags

gold nanoparticles

SARS-CoV-2

immunosensor

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