Combined negative dielectrophoresis with a flexible SERS platform as a novel strategy for rapid detection and identification of bacteria

Abstract

Surface-enhanced Raman spectroscopy (SERS) is a vibrational method successfully applied in analytical chemistry, molecular biology and medical diagnostics. In this article, we demonstrate the combination of the negative dielectrophoretic (nDEP) phenomenon and a flexible surface-enhanced Raman platform for quick isolation (3 min), concentration and label-free identification of bacteria. The platform ensures a strong enhancement factor, high stability and reproducibility for the SERS response of analyzed samples. By introducing radial dielectrophoretic forces directed at the SERS platform, we can efficiently execute bacterial cell separation, concentration and deposition onto the SERS-active surface, which simultaneously works as a counter electrode and thus enables such hybrid DEP-SERS device vibration-based detection. Additionally, we show the ability of our DEP-SERS system to perform rapid, cultivation-free, direct detection of bacteria in urine and apple juice samples. The device provides new opportunities for the detection of pathogens.

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Acknowledgements

The authors are grateful for the financial support from the Foundation for Polish Science (FNP) under grant Team-Tech/2017-4/23 (POIR.04.04.00-00-4210/17-00).

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All experiments were performed in compliance with the relevant laws and institutional guidelines. The protocol of study was approved by the Ethics and Bioethics Committee of Cardinal Stefan Wyszyński University in Warsaw, Poland. Informed consent was obtained from all patients.

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Nowicka, A.B., Czaplicka, M., Szymborski, T. et al. Combined negative dielectrophoresis with a flexible SERS platform as a novel strategy for rapid detection and identification of bacteria. Anal Bioanal Chem (2021). https://doi.org/10.1007/s00216-021-03169-y

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Keywords

  • Surface-enhanced Raman spectroscopy
  • SERS
  • Flexible SERS platform
  • Dielectrophoresis
  • Escherichia coli
  • Urine