Two phenanthroimidazole turn-on probes for the rapid detection of selenocysteine and its application in living cells imaging.

Detection of selenocysteine (Sec) content in cells by fluorescence probe is of great significance for the identification of human related diseases. To achieve fast and sensitive detection of Sec, two isomers A4 and B4 as turn-on fluorescent probes to detect Sec were designed and synthesized. Both A4 and B4 display fast turn-on response, high selectivity and sensitivity toward Sec, which can be applied for fluorescence imaging of Sec in living cells. Compared with B4, A4 has a larger Stokes shift (125 nm), wider pH range (5-10) and lower detection limit (65.4 nM) due to its ESIPT (excited state intramolecular proton transfer) effect. In view of the detection performance of these two probes, they can be used as effective tools for detecting Sec in biological systems.

A Red Emissive Fluorescent Turn-on Sensor for the Rapid Detection of Selenocysteine and Its Application in Living Cells Imaging.

The content of selenocysteine in cells has an important effect on a variety of human diseases, and the detection of selenocysteine by fluorescent sensors in vivo has shown many advantages. In order to further develop fast-reaction-time, good-selectivity, and high-sensitivity long-wavelength selenocysteine fluorescent sensors, we designed and synthesized the compound YZ-A4 as a turn-on fluorescent sensor to detect the content of selenocysteine. The quantitative detection range of the sensor YZ-A4 to selenocysteine was from 0 to 32 µM, and the detection limit was as low as 11.2 nM. The sensor displayed a rapid turn-on response, good selectivity, and high sensitivity to selenocysteine. Finally, we have demonstrated that YZ-A4 could be used for fluorescence imaging of selenocysteine in living cells.