This is a great biological question! It asks a lot about how empirical science is done in the field of modern biology! I'm glad we encourage such questions from curious people who want to learn more.
All viruses are coated with proteins and contain genetic material which can either be DNA or RNA. Since both nucleic acids have phosphodiester bonds, the genetic material provides a partial negative charge to the virus. The viral nucleic acid genomes are wrapped in proteins that can be neutral, negative, or positive in charge. Therefore, the net charge of a virus depends upon the cumulative charges of the genetic material and the protein.
So the electric charge of a virus particle depends on the constitutive parts of the virus of interest; particularly if enveloped or non-enveloped; the outward-facing heads of the phospholipid bilayer membrane of an enveloped virus will carry a negative charge.
Two references in the above paper may help with a deeper dive into the subject:
- Lodish H. et al. Molecular Cell Biology (ed 4.). (W. H. Freeman, New York, 2000). (Google Scholar)
- Michen B. & Graule T. Isoelectric points of viruses B. J Applied Micb. 109, 388–397 (2010). (PubMed) (Google Scholar)
I couldn't find any papers on the electrical properties of novel coronavirus specifically. But looking into SARS-CoV may be suggestive of general properties. Its envelope proteins have a positive charge that help with targeting and infecting ACE2-expressing cells (https://clarivate.com/wp-content/uploads/dlm_uploads/2020/01/CORONAVIRUS-REPORT-1.30.2020.pdf).