A modified Raman multidimensional spectroscopic signature of blood to account for the effect of laser power

Raman spectroscopy has been used for the development of a universal method for the identification of traces of all major body fluids. Multidimensional spectroscopic signatures, which account for the intrinsic sample heterogeneity and variations between donors, have been described for blood, semen, saliva, vaginal fluid and sweat. Here, we report on a shortcoming of the existing spectroscopic signature of blood due to the effect of laser power. The issue is the result of the previously discovered phenomenon of photoinduced hemoglobin aggregation. An investigation of this effect on the performance of the Raman signature is reported along with a remediating modification. This adjustment is demonstrated to extend the application of the multidimensional signatures to spectra obtained under low laser power conditions while preserving the signature's specificity.