Spectral Phasor Analysis for UV-Excited Autofluorescence in Turbid Media: Implications for Cellular Metabolic Assessment in Tissue Sensing*

UV-excited autofluorescence spectroscopy offers a sensitive approach for assessing cellular NADH/NADPH status in turbid media like biological tissues, despite challenges from background fluorescence and optical absorption. This study utilizes spectral phasor analysis on UV-excited autofluorescence emission from yeast cells suspended in complex turbid environments, demonstrating that the approach can effectively differentiate between cellular response to functional modifiers like cyanide and changes in optical absorption. Preliminary autofluorescence measurements in tissue showcase the potential for cellular metabolic monitoring in tissue for non-invasive biophysical and biomedical applications. Plans for constructing a hyperspectral imaging system to combine spectral and imaging modalities are also presented.