Synthesis and application of intercellular Ca2+-sensitive fluorescent probe based on quantum dots.

A novel Ca(2+)-sensitive fluorescent probe was synthesized and characterized with a coupled method that coupled di[2-(N,N-dicarboxylmethyl)amino]ethyl ether (EGTA) to the surface of mercaptoethylamine-modified CdTe quantum dots (CdTe/MA-EGTA QDs). The application of this probe to detect intercellular Ca(2+) change in the leaf cells of Arabidopsis thaliana was studied. Results from transmission electron micrographs showed that the particle size of CdTe/MA-EGTA was about 3-4 nm; the fluorescent spectrum indicated that the excitation spectral ranged from 350 to 490 nm with a narrow and symmetric emission spectral peak at 565 nm when excited by 400 nm, and capillary electrophoresis demonstrated that CdTe/MA-EGTA was obtained by a coupling reaction.