A ratiometric fluorescent probe for rapid and sensitive detection of biothiols in fetal bovine serum

Herein, a ratiometric turn-on fluorescent probe for sensitive detection of biothiols was designed. The probe consisted of two parts: one was rhodamine B serving as a fluorescence reference, and the other was coumarin derivative as the responsive fluorophore with an acrylate group for biothiols recognition. The response was based on the mechanism of Michael addition and intramolecular cyclization reaction, and the probe showed ratiometric and sensitive response to biothiols. Especially, the detection limit of this probe for cysteine was found to be 0.13 μΜ. More importantly, the probe showed the advantage of fast response, of which the fluorescence intensity can reach the maximum within 10 min. The ratiometric fluorescent probe has been successfully applied for the determination of biothiols in fetal bovine serum samples and the result was in good agreement with that tested by Ellman method.