Coumarinocoumarin-Based Two-Photon Fluorescent Cysteine Biosensor for Targeting Lysosome

Authors:

Abstract
Coumarinocoumarin, one of the coumarin derivatives, is easy to synthesize and have rich modification sites. The large conju-gate plane of coumarinocoumarin make it has more excellent optical property than conventional coumarin, for example, the two-photon fluorescence property. So, the coumarinocoumarin-based probe (CCy) has been designed and synthesized, which is the first lysosomal targeting fluorescent biosensor for cysteine. This probe was prepared by a 3-step procedure as a latent fluorescence probe to achieve high sensitivity and fluorescence turn-on response toward cysteine (Cys) over homocys-teine (Hcy), glutathione (GSH) and other various natural amino acids under physiological conditions. Upon addition of Cys to the solution of CCy, remarkable enhancement on 520 nm of fluorescence spectra can be monitored. This probe was then successfully used for fluorescence imaging of Cys in mice organ tissues and HeLa cells, and quantitative determination had been achieved within a certain range, which proved the permeability of CCy. The concentration of Cys in animal serum was measured and the viability exceeded 80%, indicating that CCy can be a biocompatible and rapid probe for Cys in vivo. Simul-taneously, its ability to detect Cys in lysosome has been validated by its lysosomal targeting.
Funding Information
  • National Natural Science Foundation of China (21431002)

This publication has 46 references indexed in Scilit: