Compositional Contrast of Biological Materials in Liquids Using the Momentary Excitation of Higher Eigenmodes in Dynamic Atomic Force Microscopy

Xin Xu, Purdue University - Main Campus
John Melcher, Purdue University - Main Campus
Sudipta Basak, Purdue University - Main Campus
R. Reifenberger, Birck Nanotechnology Center, Purdue University
Arvind Raman, Birck Nanotechnology Center, Purdue University

Abstract

Atomic Force microscope (AFM) cantilevers commonly used for imaging soft biological samples in liquids experience a momentary excitation of the higher eigenmodes at each tap. This transient response is very sensitive to the local sample elasticity under gentle imaging conditions because the higher eigenmode time period is comparable to the tip-sample contact time. By mapping the momentary excitation response, we demonstrate a new scanning probe spectroscopy capable of resolving with high sensitivity the variations in the elasticity of soft biological materials in liquids.

Discipline(s)

Nanoscience and Nanotechnology