Biological & Soft Matter Seminar: Terra incognita in autofluorescence of biosystems: novel physical mechanisms and applications

Zoom: https://us02web.zoom.us/j/88904888353?pwd=dDIwaXRxSjlsVElkR0dXdTNPTGhnZz09

Abstract: 

Autofluorescence of biomolecules, cells and tissues is a classical phenomenon widely used in biomedicine and biomedical diagnostics. The main advantage of endogenous (intrinsic) fluorescence is the possibility to perform label-free analysis, without using exogenous probes. Hence, the photophysics and optical properties of endogenous chromophores fluorophores such as hemoglobin, NAD(P)H, flavins, melanin, aromatic amino acids etc. became a textbook knowledge. However, the classical interpretation of autofluorescence formation lacks understanding of several important phenomena. Firstly, the origin of ubiquitous fluorescence emission from tissues in the red and NIR spectral ranges is unknown. This effect is extremely significant for biophotonics due to its relevance to background formation in Raman spectra and predictive capabilities for detecting tumor margins. Secondly, a lively discussion occurs in the literature about the emergence of visible fluorescence in peptides and proteins following their aggregation, as well as during self-assembly of metabolites in vitro and in vivo. The origin of this effect is supposed to originate from charge transfer or proton transfer processes, excitonic interactions or formation of oxidation products. These and some other recent findings will be used to demonstrate that the research area of autofluorescence is continuously evolving, and despite decades of research, there is still plenty of space for developing novel diagnostic methods based on endogenous fluorescence contrast both for studying intermolecular interactions and for clinical research.