Department of Applied Physics, Osaka University, Suita, Osaka 565-0871, Japan,;Joint Research Center for Atom Technology, Higashi 1-1-4, Tsukuba, 305-0046, Japan
Abstract:
We investigated fluorescence imaging using a near-field scanning optical microscope which uses a laser-stabilized gold nanoparticle as a near-field probe. This microscope is suitable for observations of biological specimens in aqueous solutions because the probe particle is held by a noncontact force exerted by a laser beam. Theoretical calculations based on Mie scattering theory are presented to evaluate the near-field enhancement by a gold particle of 40 nm diameter. We also present fluorescence images of a single fluorescent bead and discuss the near-field contribution to the fluorescence image in this type of microscope.