A fluorescent probe for biothiols based on the conjugate addition of thiols to α,β-unsaturated ester.
A sensitive fluorogenic probe 1 for biothiols was developed based on the Michael addition reaction. The probe 1 was readily synthesized via the reaction of 2-(4'-hydroxyphenyl) benzimidazole (HPBI) with acryloyl chloride and shows weak fluorescence emission. Upon mixing with biothiols, the fluorescence of 1 is significantly enhanced due to the conjugate addition of thiols to the α,β-unsaturated carbonyl moiety, thus eliminating the photoinduced electron transfer (PET) quenching of the fluorophore by the intramolecular carbon-carbon double bond. Cysteine (Cys) was selected as the representative thiol in the spectral experiment. A good linear relationship was obtained from 1.0 to 30.0 µmol L(-1) for Cys and the detection limit was 0.17 µmol L(-1). Furthermore, probe 1 was highly selective for biothiols without the interference of some biologically relevant analytes and has been applied to detecting biothiols in human urine samples.
Du
Jun
J
Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Institute of Analytical Science, Department of Chemistry, Northwest University, Xi'an 710069, China.
Yang
Zhe
Z
Qi
Haiping
H
Yang
Xiao-Feng
XF
D004952:Esters / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013050:Spectrometry, Fluorescence; D013055:Spectrophotometry, Infrared; D013438:Sulfhydryl Compounds / Q000737:chemistry*
D004952:Esters; D005456:Fluorescent Dyes; D013438:Sulfhydryl Compounds