Fluorophore Release from a Polymethinic Photoremovable Protecting Group Through a Nonlinear Optical Process

Abstract

AbstractTriggering the release of chemical species through the use of light is crucial for modern microscopy applications, such as single‐molecule localization and, in general, in the regulation of molecular effectors. Herein, we demonstrate a nonlinear‐optical scheme for the control of photorelease. Our system consists of a two‐photon‐absorbing photoremovable protecting group (PPG) bonded to a second chromophore which undergoes photo‐induced detachment and activation upon excitation with λ=850 nm femtosecond pulses. The two‐photon PPG section consists of a cyanine‐type dye, and the releasable section is a highly fluorescent derivatized anthracene chromophore bonded to the cyanine through a photolabile etheric‐meso‐carbon bond. This method allows for the release of a fluorophore following a spatially localized two‐photon excitation event. Both the excitation energy and the long lifetime of the upper excited states of the PPG chromophore are thought to be involved in the release process.