A dual responsive fluorescent probe for selective detection of cysteine and bisulfite and its application in bioimaging

A coumarin-based dual responsive fluorescent probe with a simple structure was developed for the detection of Cys and HSO₃ ^-. Under simulated physiological conditions, Cou-F displayed an on-off fluorescence response to Cys at 521 nm and an off-on fluorescence response to HSO₃ ^- at 500 nm. Furthermore, Cou-F had the advantages of high sensitivity, strong specificity and rapid response. The detection limits of Cou-F toward Cys and HSO₃ ^- were 0.54 μM and 0.65 μM, respectively. Cou-F enabled high selective responses to Cys and HSO₃ ^- over other biologically related species. The response times of Cou-F toward Cys and HSO₃ ^- were 80 s and 100 s. The fluorescence imaging of Cys and HSO₃ ^- was achieved in living RAW246.7 cells.

A novel near-infrared fluorescent probe for the dynamic monitoring of the concentration of glutathione in living cells

In this study, a water-soluble, near-infrared fluorescent probe (EQR-S) was designed for the measurement of the glutathione (GSH) concentration. Responses of different interfering substances to the developed probe were investigated, and the luminescence mechanism was examined by theoretical calculations. Results revealed that EQR-S can be applied for the rapid, sensitive determination of the GSH concentration with a detection limit of 69 nM. Based on the above advantages, EQR-S was successfully applied to investigate the fluctuation in the GSH concentration of living cells under high-temperature stress.

A Hybrid Coumarin-Semifluorescein-Based Fluorescent Probe for the Detection of Cysteine

A new type of turn-on fluorescent probe CF-AC for the detection of Cys was firstly reported. The probe exhibited an excellent response to Cys with high selectively and sensitivity. In the presence of Cys, two fluorescence emission peaks at 525 nm and 650 nm appeared accompanied by the fluorescence color change from blue to red. Morever, the probe had good biocompatibility and could be successfully used for fluorescence imaging of Cys in MCF-7 cells.

A tri-site fluorescent probe for simultaneous sensing of hydrogen sulfide and glutathione and its bioimaging applications

Hydrogen sulfide (H₂S) and biothiol molecules, such as glutathione (GSH), cysteine (Cys), and homocysteine (Hcy), play an important role in biology.