https://doi.org/10.1140/epjst/e2014-02245-4
Regular Article
Using the atomic force microscope as a nanomechanical partner to support evanescent field imaging
1 Biomedical Engineering Department, Texas A&M University, College Station, Texas 77843, USA
2 Dalton Cardiovascular Research Center and Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri 65211, USA
a e-mail: kmeissner@bme.tamu.edu
Received: 10 June 2014
Revised: 4 August 2014
Published online: 6 October 2014
Quantum Dot (QD)/microsphere structures supporting Whispering Gallery Modes (WGMs) are attached to Atomic Force Microscope (AFM) cantilevers for characterization of the evanescent field around the QD/microsphere and utilization of the evanescent field for sensing at the apical surface of live cells. Following laser excitation, QD emission couples to WGMs that circumnavigate the microsphere via total internal reflection at the internal surfaces of the microsphere. The resulting evanescent field is characterized utilizing the high spatial control of an AFM in approaching a dye monolayer on a test surface. The measured evanescent field extends approximately 50 nm from the microsphere surface, matching theoretical predictions. This system was then used to sense the accumulation of integrin and formation of focal adhesions at the apical surface of cells.
© EDP Sciences, Springer-Verlag, 2014
