title: A coumarin-based fluorescent probe for biological thiols and its application for living cell imaging.
abstract: In this work, compound 1 has been rationally designed and synthesized as a new fluorescent probe for biological thiols. Notably, probe 1 has almost no background fluorescence (Φf < 0.0001) in aqueous solutions; however, it exhibited fluorescence turn-on response to thiols with high sensitivity (a 246-fold fluorescence enhancement and a low detection limit of 0.22 μM for Cys). Moreover, probe 1 showed excellent thiol specificity over other biologically relevant species. The kinetic studies indicated that the probe responded to thiols rapidly, and the pseudo-first-order rate constants of probe 1 reaction with Cys, Hcy, and GSH were determined to be 1.85842, 0.67656, and 0.51519 min(-1), respectively. A possible detection mechanism was proposed to involve the Michael addition of the thiol to the α,β-unsaturated ketone, followed by a cleavage of the hemiketal group, thereby leading to the formation of a fluorescent 7-hydroxyl coumarin derivative. Furthermore, the optical responses of probe 1 to thiols were studied by TD-DFT calculations. Finally, probe 1 has been successfully applied to the detection of biological thiols in human blood serum. And the intracellular imaging applications established that probe 1 can be used to detect different concentrations of intracellular thiols in living cells.
authors.affiliation: Functional Molecular Materials Research Centre, Scientific Research Academy & School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, P. R. China. Linglianglong@gmail.com Chizhang@ujs.edu.cn.
authors.forename: Lingliang
authors.initials: L
authors.lastname: Long
authors.forename: Liping
authors.initials: L
authors.lastname: Zhou
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Suci
authors.initials: S
authors.lastname: Meng
authors.forename: Aihua
authors.initials: A
authors.lastname: Gong
authors.forename: Fengyi
authors.initials: F
authors.lastname: Du
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
mesh_terms: D002470:Cell Survival; D003374:Coumarins / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008958:Models, Molecular; D015394:Molecular Structure; D010190:Pancreatic Neoplasms / Q000737:chemistry* / Q000473:pathology; D011789:Quantum Theory; D013438:Sulfhydryl Compounds / Q000097:blood*
chemical_list: D003374:Coumarins; D005456:Fluorescent Dyes; D013438:Sulfhydryl Compounds; C030123:coumarin