Biomedical Engineering Reference
In-Depth Information
Characterization of Nanoscale Biological
Systems: Multimodal Atomic Force Microscopy
for Nanoimaging, Nanomechanics,
and Biomolecular Interactions
Arjan P. Quist and Ratnesh Lal
1
Introduction
Complexity in biological systems requires coordinated research efforts using
techniques and approaches that are amenable to multiscale (from nano to micro and
beyond) and multidimensional (including their structure, activity, and function)
microsystems (e.g., cell membrane, cell organelles, biomacromolecules, and their
individual as well as integrated functioning). Major experimental designs and
discoveries in biological sciences have usually been preceded by major discoveries
in physicochemical sciences and engineering. Our understanding of biological
systems at the time and length scale of micrometer and above is reasonable. Scaling
down those systems at nanometer level is challenging and mostly unexplored as yet.
The classic correspondence theory of nanoscale and microscale phenomena in
physical systems is not likely to be valid for biological systems given the layers of
complexity in the biological systems. Hence, one needs to examine biological
systems at nanoscale in both structural and temporal domains.
A major limitation of the existing techniques to obtain nanoscale structural
information about biological systems, which are all hydrated by nature, is that
these techniques are unsuitable for the study of hydrated systems. The second
hurdle of the existing techniques is that they lack precision and resolution for
interfaces, like biological membranes, subcellular organelles, connected tissues,
and biomacromolecules.
Traditional tools used to obtain structural information, such as electron micros-
copy, X-ray diffraction, nuclear magnetic resonance (NMR), and infrared spectros-
A. P. Quist
Richmond Chemical Corporation , Oak Brook , IL, USA
R. Lal (
*
)
Departments of Mechanical and Aerospace, and Bio-engineering,
University of California San Diego, La Jolla , CA, USA
e-mail: rlal@ucsd.edu
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