Label-free spectroscopic detection of membrane potential using stimulated Raman scattering

Hyperspectral stimulated Raman scattering microscopy is deployed to measure single-membrane vibrational spectrum as a function of membrane potential. Using erythrocyte ghost as a model, quantitative correlation between transmembrane potential and Raman spectral profile was found. Specifically, the ratio between the area under Raman band at similar to 2930 cm(-1) and that at similar to 2850 cm(-1) increased by similar to 2.6 times when the potential across the erythrocyte ghost membrane varied from +10mV to similar to 10 mV. Our results show the feasibility of employing stimulated Raman scattering microscopy to probe the membrane potential without labeling. (C) 2015 AIP Publishing LLC.