Applications of Atomic Force Microscope in Biological and Biomedical Research

Abstract: In this seminar, two examples will be presented to illustrate how a modern instrument, atomic force microscope (AFM), can be applied to solve challenging problems in the biological and biomedical field. In the first example, AFM was used to perform nanoindentation on viruses to gain a quantitative understanding of their elasticity. Results from these studies showed a close relationship between mechanical and biological properties of living organisms. In the second example, in situ AFM was used to direclty observe the self-assembly of peptoid molecules and investigate self-assembly mechanisms. We showed that slight changes in molecular sequence led to a switch from classical nucleation to a non-classical process, where disordered precursors are transformed into ordered nuclei before growing. Our results shed new light on non-classical crystallization mechanisms and have implications in understanding living systems and drug formulations, as well as in predictable design of self-assembling polymer systems for applications in energy storage, nanoelectronics, sensing, filtration and biomedical devices.