Combined force and photonic probe microscope with single, molecule sensitivity

Direct integration of atomic force microscopy (AFM) imaging with single molecule optical detection promises to combine the resolving power of AFM with the chemical identification capabilities of optical techniques. We,present a straightforward experimental approach to achieving such integration. Our design allows simultaneous acquisition of topographical images and optical images with single molecule sensitivity at any region of. the optical spectrum. We describe an instrument that combines atomic force microscopy and scanning confocal optical microscopy in a single multifunctional setup that maximizes the use of commercially available parts. To build this instrument we replaced the built-in piezoscanner of a commercial optical microscope-AFM platform with an external scanner that translates the sample. We also added a simple circuit to the setup that modulates the AFM-head laser and synchronizes collection of the AFM and optical data in interleave scanning mode. Finally, we demonstrate the technique's identification capabilities using a model system of dye-labeled beads. (C) 2003 American Institute of Physics.