A novel fluorescent probe with large Stokes shift for the detection of viscosity changes and its imaging in living cells.

As an important cellular microenvironmental parameter, viscosity could reflect the status of living cells. Small molecular fluorescent probes are a vital tool to measure the change of viscosity in living cells. A novel fluorescence probe ZL-1 with a large Stokes shift (in methanol it reached to 153 nm and in glycerol it reached to 125 nm) and excellent sensitivity toward viscosity was developed. The sharp enhancement of the emission intensity for the probe ZL-1 from low viscous methanol to high viscous glycerol indicated that the probe ZL-1 could respond to the viscosity variations. Moreover, the probe ZL-1 has been successfully utilized to detect of the viscosity variations in living cells.

A novel fluorescent probe for rapid detection of sulfur dioxide in living cells.

Sulfur dioxide is one of the reactive sulfur species, which has significant physiological functions in cells. Some physiological processes are closely related to SO2 in organisms, and the high concentration of SO2 in living cells can cause many diseases. In order to investigate the unique function of SO2 at the subcellular level, developing a molecular tool which could detect of SO2 within organelles is imperative. Hence, we developed a cationic dye named HQ-SO2 as a new fluorescent probe to specifically monitor SO2 , which was easy to obtain through one-step reaction. It took Michael addition reaction as the mechanism of reaction for detection of SO2 . In addition, this probe showed a series of highly favorable properties such as rapid response rate, low cytotoxicity, high selectivity, low detection limit, and good photostability, which enabled the probe to track SO2 in living cells.

A novel cysteine fluorescent probe with large stokes shift for imaging in living cells, zebrafish and living mice.

The small molecule biological thiols, such as Cysteine (Cys), homocysteine (Hcy), and glutathione (GSH), play crucial roles in maintaining various cellular vital activities. In the organism, abnormal levels of small-molecule biological thiols have been associated with a variety of diseases. Therefore, quantitative determination of biological thiols, especially Cys, is significant for understanding their functions in various biological processes. Thus, in this work we designed a new fluorescent probe Ty-Cys1 with a large Stokes shift of 207 nm to monitor Cysteine. The maximum absorption wavelength of Ty-Cys1 was 418 nm, and the maximum emission wavelength was 625 nm. Significantly, the novel probe Ty-Cys1 was effectively in detecting of Cys changes in living cells, zebrafishes, and living mice.