Similar to the Israeli- developed spectroscopy-based one-minute breathe analyzer to detect coronavirus, the Dutt Lab at ACTREC- Tata Memorial Centre developed a proof of principle study using Raman Spectroscopy, published in the Journal of Biophotonics. The group used non-infectious RNA viruses to spike in human saliva and analyzed using conventional Raman Spectroscopy, i.e., using no additional reagent to enhance the signal. Based on an unbiased statistical analysis of all the 1400 spectra obtained for each sample, Dr. Dutt's group found a set of 65 spectra was adequate to identify the viral positive signal. Interestingly, most of these spectra were specific to the RNA molecule. This is a unique concept with a prediction accuracy of 91.6% (acceptable based on other approved Raman-based diagnostics). Dr. Dutt’s group also developed an automated tool, “RVD: RNA Virus Detector,” using a GUI interface to streamline the analysis. This tool is freely downloadable from here: 

http://www.actrec.gov.in/pi-webpages/AmitDutt/RVD/RVD.html. This tool, the first of its kind, takes raw data from a Raman Spectrometer analysis based on the 65 spectra signature and provided an objective output if viral RNA is present or absent in the sample—currently in use by over 40 labs across ten different countries (based on the online registration done before downloading the tool).