Biological Scanning Probe Microscopy

Chemical Force Microscopy

We are developing Chemical Sensor Microscopy with the ability to map chemical heterogeneity with nanoscale resolution. In particular, we are building a proficiency in the use of functionalized Atomic Force Microscopy (f-AFM) probes, which present an attractive means of performing nanometer scale chemical imaging on various samples such as polymers, biomimetic materials, and biological membranes. In f-AFM, conventional AFM probes, or carbon nanotube probes, may be modified to provide well-defined surface chemistry at the probe tip. In either case, we employ probe tips covered by particular chemical groups. These functional groups (e.g., CH₃, NH₂, COOH, or more exotic biological molecules) produce interactions between the probe and specimen surface that reflect the known tip chemistry and the local chemistry of the sample. By harnessing these interactions, f-AFM images, generated by scanning the probe tip over the sample surface, are used to map spatial heterogeneity in the specimen chemistry with nanometer resolution. Current projects are being pursued through a highly multidisciplinary approach involving development of f-AFM probe functionalization protocols, including rigorous characterization of f-probes; characterization of a comprehensive set of “calibration” samples; and development of f-AFM techniques that provide reliable, reproducible image contrast related directly to sample chemistry.

Biological Near-field Scanning Optical Microscopy

See Near-field Scanning Optical Microscopy

Single Molecule Probes for Biophysics and Biology