Investigation of nanolocal fluorescence resonance energy transfer for scanning probe microscopy

Fluorescence resonance energy transfer (FRET) has been observed between don or dye molecules deposited onto the sample surface and acceptor dye molecul es deposited onto the scanning near-field optical microscope (SNOM) or atom ic force microscope tip. FRET was observed only when the tip acquired a con tact with the sample and took place in a region of few tens of square nanom eters in size when thousands (hundreds) of molecules are involved. In view of the obtained results, the perspectives for the construction of a one-ato m FRET SNOM are described. (C) 1999 American Institute of Physics. [S0003-6 951(99)03823-1].