Raman-dielectrophoresis goes viral: towards a rapid and label-free platform for plant virus characterization

Front Microbiol. 2023 Nov 22:14:1292461. doi: 10.3389/fmicb.2023.1292461. eCollection 2023.

Abstract

An innovative spectroscopic method that allows to chemically and structurally characterize viruses directly in suspension within few minutes was developed. A library of five different plant viruses was obtained combining dielectrophoresis (DEP), performed with a device specifically designed to capture and agglomerate virus particles, and Raman spectroscopy to provide a chemical fingerprint of virions. The tested viruses, purified from infected plants, were chosen for their economic impact on horticultural crops and for their different morphological and structural features. Using the Raman-DEP device, specific profiles for each virus were successfully obtained, relying on chemical differences occurring even with genetically similar viruses belonging to the same taxonomic species and morphologically indiscernible by transmission electron microscopy (TEM). Moreover, we investigated the potentiality of Raman-DEP to follow dynamic changes occurring upon heat treatment of tobacco mosaic virus (TMV) particles. Raman peak deviations linked to TMV coat protein conformation were observed upon treatment at temperatures equal or higher than 85°C, substantiating the rod-to-spherical shape transitions observed by TEM and the concomitant drastic loss of infectivity following plant inoculation. Overall, the Raman-DEP method can be useful for the characterization of virus (nano)particles, setting the basis to create a database suitable for the study of viruses or virus derived-nanoparticles relevant for the agricultural, medical, or biotechnological fields.

Keywords: Raman spectroscopy; TMV; dielectrophoresis; plant viruses; virus-derived nanoparticles.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. The present work has been supported by the following projects: (1) “20NET02 Food-MetNet”, funded by EURAMET EMPIR program co-financed by the Participating States and the EU Horizon 2020 research and innovation program, (2) NUTRAGE, CNR project FOE-2021 DBA.AD005.225, (3) “ON Foods - Research and innovation network on food and nutrition Sustainability, Safety and Security – Working ON Foods” (code PE00000003) within the National Recovery and Resilience Plan (NRRP) Mission 4 Component 2 Investment 1.3 - Call for proposals No. 341 of 15 March 2022 of Italian MUR, funded by the European Union – NextGenerationEU, and (4) “Agritech National Research Center” funded by the European Union Next-GenerationEU (PIANO NAZIONALE DI RIPRESA E RESILIENZA (PNRR) – MISSIONE 4 COMPONENTE 2, INVESTIMENTO 1.4 – D.D. 1032 17/06/2022, CN00000022). This manuscript reflects only the authors’ views and opinions, neither the European Union nor the European Commission can be considered responsible for them.