Biological applications of scanning probe microscopies.

Biological Applications of Scanning Probe Microscopy. Scanning probe microscopes (SPMs) have now become established as the foremost tools in the imaging of surfaces and surface–confined structures at up to angstrom resolution. Whilst spectroscopic methods such as Raman, ellipsometry and surface plasmon resonance continue to provide useful information on interfaces, they remain tools of restricted spatial resolution and are accordingly limited to measurements of bulk averages. In contrast, proximal probe methods offer unrivalled imaging of surfaces and with it the ability to address individual molecular species. As scanning probe technology has developed there has been significant progress in the analysis of biological samples, varying in scale from individual biological polymers to complex cellular systems. More recently, the application of scanning probe microscopes has developed beyond imaging into areas such as nanoscale electrical measurement and direct molecular delivery and manipulation.