Optical diagnosis of typhoid infection in human blood sera using Raman spectroscopy

Raman spectroscopy has the ability to provide highly specific disease diagnostic results based on intrinsic molecular signatures in biological samples. We recorded variation in spectral range (540-1830 cm(-1)) for 60 Salmonella typhi-infected and 60 healthy sera samples at 785 nm. Analysis reveals characteristic peaks at 630, 1099, 1144, 1343, 1692, 1711, and 1746 cm(-1). Moreover, statistical analysis using principal component analysis successfully separated healthy and diseased samples. Our results provide an initial indication of possibility to use these typhoid specific serum markers for the optical diagnosis of typhoid.