title: Two-photon fluorescent probe derived from naphthalimide for cysteine detection and imaging in living cells.
abstract: A maleimide coupling naphthalimide was reported as new two-photon fluorescent (TPF) probe for cysteine (Cys). The probe was weakly fluorescent itself due to the donor-excited photoinduced electron transfer (d-PET). After reaction with Cys, d-PET process was blocked and fluorescence enhancement of the probe was observed at 470 nm. The d-PET principle was rationalized by theoretical calculations with density functional theory and time-dependent density functional theory. Thiol-maleimide addition between the probe and Cys was confirmed by (1)H NMR and mass spectrum measurements. TPF analysis demonstrated a 24.7-fold emission increase of the probe induced by Cys upon excitation at 760 nm. The two-photon action cross-section of probe-Cys adduct at 760 nm reached 42 GM compared to 1.7 GM for free probe. The probe showed high sensitivity and selectivity to Cys over other potential interferences; especially it had the capability to discriminate Cys from glutathione and homocysteine. Through TPF imaging, the probe was successfully applied in the detection of Cys in living cells.
authors.affiliation: Institute of Pharmaceutical Analysis, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430072, China.
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Chemistry, Wuhan University, Wuhan 430072, China.
authors.forename: Yuwen
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Institute of Pharmaceutical Analysis, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430072, China. Electronic address: chirolab@whu.edu.cn.
authors.forename: Shucai
authors.initials: S
authors.lastname: Liang
mesh_terms: D003545:Cysteine / Q000032:analysis* / Q000737:chemistry; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D005978:Glutathione / Q000032:analysis; D006367:HeLa Cells; D006710:Homocysteine / Q000032:analysis; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008301:Maleimides / Q000737:chemistry; D008956:Models, Chemical; D015336:Molecular Probe Techniques; D053644:Naphthalimides / Q000737:chemistry*; D017785:Photons; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods; D013056:Spectrophotometry, Ultraviolet; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D008301:Maleimides; D053644:Naphthalimides; D013438:Sulfhydryl Compounds; D006710:Homocysteine; C043592:maleimide; D005978:Glutathione; D003545:Cysteine
keywords: Cell imaging; Cysteine; Naphthalimide; Theoretical calculations; Two-photon fluorescent probe