Live cell imaging and spectroscopy are important areas of biophysical and biomedical research that visualize living cells and their internal structures, study cell processes and functions of individual molecules under natural conditions. To this end, live cell studies with Raman spectroscopy (RS) have recently attracted great interest, since RS provides information about bond vibrations and, thus, the structure of biomolecules in vivo with no effect on cell's integrity.
Surface Enhanced Raman spectroscopy (SERS) is another Raman tool which utilizes the effect of the plasmon resonance and charge transfer when the studied molecule is found in the vicinity of a nanoparticle (NP) or a nanostructured surface, usually silver (Ag) or gold (Au). Due to the plasmon resonance and the charge transfer the intensity of Raman signal is greatly enhanced. This has made possible studies of molecules at concentrations much below 10-6 M and so-called “single-molecule studies”. The NP plasmon resonance occurs only when the distance between the NP surface and the studied molecule is relatively small and its intensity decreases dramatically for the distances greater than 15 nm from NP surface.
In vivo Raman spectroscopy
- We develop in vivo experimental approach based on surface-enhanced Raman spectroscopy (SERS) to perform localization and study of hemoglobin properties and signaling pathways in living erythrocyte;
- We study the relation between erythrocyte morphology, properties of plasma membrane and hemoglobin (Hb) ability to bind and to release oxygen under normal and pathological conditions;
- We investigate a modulation of hemoglobin affinity to oxygen by nitric oxide (NO), submembrane and cytosolic processes in erythrocytes and mechanisms of regulation of oxygen delivery to tissues in order to specify biomarkers of pathological conditions of cardiovascular system;
- We optimize SERS experimental conditions to study redox state of isolated mitochondria;
- We study redox state of reduced cytochromes c, c1 and b of complexes II and III in mitochondria of live cardiomyocytes;
- We study redox changes in c- and b-type cytochromes and semiquantitatively estimate the amount of oxygenated myoglobin in a perfused rat heart;
- We study redox changes in c- and b-type cytochromes in brain slices.