Clinical applications of spectroscopic techniques in conjunction with multivariate analysis in virus diagnosis

In view of the global pandemic that started in 2020, caused by COVID-19, the importance of the existence of fast, reliable, cheap diagnostic techniques capable of detecting the virus even in the first days of infection became evident. This review discusses studies involving the use of spectroscopic techniques in the detection of viruses in clinical samples. Techniques based on mid-infrared, near-infrared, Raman, and molecular fluorescence are explained and it was demonstrated how they can be used in conjunction with computational tools of multivariate analysis to build models capable of detecting viruses. Studies that used real clinical samples from 2011 to 2021 were analyzed. The results demonstrate the potential of the techniques in detecting viruses. Spectroscopic techniques, as well as chemometric techniques, were also explained. Viral diagnosis based on spectroscopy has interesting advantages compared to standard techniques such as: fast results, no need for reagents, non-destructiveness for the sample, no need for sample preparation, relatively low cost, among others. Several studies have corroborated the real possibility that, in the near future, we may have spectroscopic tools being successfully applied in viral diagnosis.