A simple and new fluorescent and colorimetric probe based on NBD–maleimide for detecting thiols in living cells

Abstract

A simple and new fluorescent and colorimetric probe bearing 7-nitrobenz-2-oxa-1,3-diazole and 4-maleimidophenol fragments for biothiols was designed and synthesized. The probe itself showed almost no background fluorescence (F F < 1 Â 10 À4 ) and displayed fluorescence turn-on response with selectivity for thiols over other relevant biological species in aqueous solutions. In addition, the probe exhibited 110 nm red-shifted absorption spectra accompanied by color changes which could be obviously distinguished by the naked eye. Furthermore, the probe showed high sensitivity towards thiols with a detection limit of 1.2 Â 10 À7 M (S/N ¼ 3) and the mechanism regarding the optical responses of the probe to thiols was explained by density function theory (DFT) calculations. Finally, the probe has been successfully used to image thiols in HeLa cells.

Dyes derived from benzo[a]phenoxazine – synthesis, spectroscopic properties, and potential application as sensors for l‐cysteine

“…It can be seen that dyes 7a to 7c exhibit high sensitivity to l ‐Cys. The lowest concentration of l ‐Cys that can be determined by the presented fluorescent probes is 0.111–0.271 μ m , which is comparable with other reported compounds .…”

“…Table 2 shows the detection limits of the tested compounds 7a to 7c for L-Cys. The lowest concentration of L-Cys that can be determined by the presented fluorescent probes is 0.111-0.271 lM, which is comparable with other reported compounds [23,26,27,[38][39][40][41][42]. The lowest concentration of L-Cys that can be determined by the presented fluorescent probes is 0.111-0.271 lM, which is comparable with other reported compounds [23,26,27,[38][39][40][41][42].…”

Covalent Modification of Biomolecules through Maleimide-Based Labeling Strategies

“…More pronounced fluorescence responses were observed with probes where the maleimide moiety was directly connected to the aromatic core of the fluorophore (6–286× in brightness, and 21–350× in quantum yield) than those having an aliphatic spacer (5–45× for the brightness, and 3–20× for the quantum yield). − While these probes are mostly used for the in vitro, in cellulo, or in plasma detection of biothiols, peptides, proteins, or antibodies, some of these probes can be used for biothiol recognition by HPLC with fluorescence monitoring. To this end, pyrene, − coumarin, BODIPY, , and N -[4-(2-phthalimidyl) phenyl] maleimide (PPM) were used for their good fluorescence responses to biothiols.…”