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.
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.
Jun
J
Du
Zhe
Z
Yang
Haiping
H
Qi
Xiao-Feng
XF
Yang
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