Visible auto-fluorescence in biological fluids as biomarker of pathological processes and new monitoring tool

Comparative optical study of biofluids(serum,urine,hemodialyste)by concentration change ofendogenous visible fluorescence substance(VFS)has been carried out.Biofluids were collectedfrom chronic kidney diseases(CKD)patients(Pts)_as well as from healthy controls(HCs).Exeitation/emission spectra are similar for all samples of biofluids differing only in intensity,which is higher for CKD Pts.Strong similarity enables the study of given biofluids from a unitedphysical platform,proposed earlier,i.e.,as nanoparticles approach.Specific spectral redistribu-tion of visible fluorescence(VF)intensity as a result of dilution is revealed.The concentrationchange of VFS by dilution of samples manifests in nonlinear dependences in the scales"VFintensity-concentration"for serum and urine and in perfect linearity for hemodialysate(HD).The latter fact can be used in monitoring of hemodialysis procedure.