Nanospectrofluorometry inside single living cell by scanning near-field optical microscopy

Near-field fluorescence spectra with subdiffraction limit spatial resolutio n have been taken in the proximity of mitochondrial membrane inside breast adenocarcinoma cells (MCF7) treated with the fluorescent dye (JC-1) by usin g a scanning near-field optical microscope coupled with a confocal laser mi crospectrofluorometer. The probe-sample distance control is based on a piez oelectric bimorph shear force sensor having a static spring constant k=5 mu N/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 MC F7 cell surface. (C) 2001 American Institute of Physics.