Photobleaching of Cy5 Conjugated Lipid Bilayers Determined With Optical Microresonators

Whispering gallery-mode optical microcavities have significantly impacted the field of label-free optical biodetection. By combining the evanescent field generated by the microcavity with biomimetic surface chemistries, it is possible to use the microcavities to study the fundamental photobleaching behavior of fluorescent molecules embedded in biomaterials. In this study, a self-assembled Cy5-conjugated lipid bilayer is formed on a spherical optical microcavity. The evanescent tail of the microsphere is used to excite the Cy5 dye molecules. Both the emission wavelength and the fluorescence intensity decrease of the Cy5-conjugated dye in the lipid bilayer are measured.