Identification of new spectral signatures associated with dengue virus infected sera

Abstract

In a quest to use Raman spectroscopy as an optical diagnostic tool, we recorded Raman spectra of 32 dengue virus (DENV)‐infected and 28 healthy sera samples in the near‐infrared spectral range (540 to 1700 cm−1) using laser at 785 nm as the excitation source. We observed clear differences in the Raman spectra of DENV‐infected sera as compared with those of healthy individuals. Here, as a result of our study, we report 12 unique Raman bands associated with DENV‐infected sera that are not reported earlier. After applying analysis of variance and t‐test (p < 0.05) on these 12 bands, six Raman bands at 630 (N‐acetylglucosamine), 883 (in‐plane bending (ring) of deoxyribose), 1218 (amide III–β conformation from C6H5–C stretching vibrations of tryptophan and phenylalanine), 1273 (amide–III), 1623 (tryptophan) and 1672 cm−1 (ceramide) were found only in the DENV‐infected sera. The remaining six Raman bands at 716 (lipids), 780 (Uracil‐based ring breathing mode), 828 (ring breathing tyrosine), 840 (α‐anomers), 1101 (ν(C–N) of lipids and DNA) and 1150 cm−1(glycogen/carotenoids) were only found in healthy sera. Two types of classification models, principal component analysis and linear discriminant analysis, were employed to develop principal component analysis–linear discriminant analysis model that has provided diagnostic accuracy 96.50%, sensitivity 93.44%, and specificity 100%. This indicates that these 12 Raman bands have the potential to be used as biomarkers for optical diagnosis of DENV infection. This study provides a new insight for future research in the field of optical diagnosis using Raman spectroscopy. Copyright © 2017 John Wiley & Sons, Ltd.