title: The study of a curcumin-resembling molecular probe for the pH-responsive fluorometric assay and application in cell imaging.
abstract: A molecular probe of DibOH (2,6-bis(4-hydroxybenzylidene)cyclohexanone) designed as the ameliorant to the curcumin was prepared in which one enol unit was removed to avoid the intramolecular hydrogen bond and thus more rigidity and better coplanarity were achieved. Deprotonation of the phenolic hydroxyl group led to the negative charge and the intramolecular charge transfer (ICT) functioned accordingly. The DibOH probe in basic conditions exhibited the absorption peak at 468 nm, which indicated a red shift of 183 nm relative to that in acid conditions and was visible as a brown color to naked eyes. The ratio of fluorescence intensity at 612 nm to that at 520 nm (I612/I520) was calculated and a clear correlation with the pH value was obtained. The density functional theory (DFT) was performed on theoretical investigation of the acidic and basic forms of DibOH. The DibOH probe was evaluated in fluorescent imaging of human breast cancer cells (MCF-7) wherein the heterogeneous distribution of the intracellular pH microenvironment was observed.
authors.affiliation: School of Chemistry & Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Decheng
authors.initials: D
authors.lastname: Xiang
authors.affiliation: School of Chemistry & Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: qhmeng@sjtu.edu.cn.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Meng
authors.affiliation: School of Chemistry & Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Heng
authors.initials: H
authors.lastname: Liu
authors.affiliation: Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Minbo
authors.initials: M
authors.lastname: Lan
authors.affiliation: CSIRO Materials Science and Engineering, P.O. Box 218, Linfield, NSW 2070, Australia.
authors.forename: Gang
authors.initials: G
authors.lastname: Wei
mesh_terms: D003474:Curcumin / Q000737:chemistry*; D003512:Cyclohexanones / Q000737:chemistry*; D004579:Electron Transport; D005470:Fluorometry / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D061986:MCF-7 Cells; D008958:Models, Molecular; D008968:Molecular Conformation; D057054:Molecular Imaging / Q000379:methods*; D015335:Molecular Probes / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry
chemical_list: C000611150:2,6-bis(4-hydroxybenzylidene)cyclohexanone; D003512:Cyclohexanones; D015335:Molecular Probes; D010636:Phenols; D003474:Curcumin
keywords: Cell imaging; Fluorescence; Molecular probe; pH-responsive