Nanospectrofluorometry Inside Single Living Cell By Scanning Near-Field Optical Microscopy

Near-field fluorescence spectra with subdiffraction limit spatial resolution have been taken in the proximity of mitochondrial membrane inside breast adenocarcinoma cells (MCF7) treated with the fluorescent dye (JC-1) by using a scanning near-field optical microscope coupled with a confocal laser microspectrofluorometer. The probe-sample distance control is based on a piezoelectric bimorph shear force sensor having a static spring constant k=5 muN/nm and a quality factor Q=40 in a physiological medium of viscosity eta =1.0 cp. The sensitivity of the force sensor has been tested by imaging a MCF7 cell surface. (C) 2001 American Institute of Physics.