Alterations of Single Molecule Fluorescence Lifetimes in Near-Field Optical Microscopy

Science  15 Jul 1994:
Vol. 265, Issue 5170, pp. 364-367
DOI: 10.1126/science.265.5170.364


Fluorescence lifetimes of single Rhodamine 6G molecules on silica surfaces were measured with pulsed laser excitation, time-correlated single photon counting, and near-field scanning optical microscopy (NSOM). The fluorescence lifetime varies with the position of a molecule relative to a near-field probe. Qualitative features of lifetime decreases are consistent with molecular excited state quenching effects near metal surfaces. The technique of NSOM provides a means of altering the environment of a single fluorescent molecule and its decay kinetics in a repeatable fashion.