title: A red-shift colorimetric and fluorescent sensor for Cu2+ in aqueous solution: unsymmetrical 4,5-diaminonaphthalimide with N-H deprotonation induced by metal ions.
abstract: 4,5-Diamino-1,8-naphthalimide (DNP)-based chemosensor was designed and synthesized. Probe specifically recognized Cu(2+) ions in neutral aqueous solution. The capture of Cu(2+) by the receptor resulted in deprotonation of the secondary amine conjugated to the 1,8-naphthalimide chromophore, so that the electron-donation ability of the "N" atom would be greatly enhanced; thus probe showed a 50 nm red-shift in absorption (from 464 nm to 514 nm) and a large colorimetric response, it also exhibited an on-off fluorescent response. Specifically, is a pH-independent sensor in the range of 6.0 to 12.0 and can be used as a probe for Cu(2+) in strong basic conditions. These results opened up new possibilities for construction of red-shift colorimetric and fluorescent sensors.
authors.affiliation: Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai, 200237, China.
authors.forename: Junhai
authors.initials: J
authors.lastname: Huang
authors.forename: Yufang
authors.initials: Y
authors.lastname: Xu
authors.forename: Xuhong
authors.initials: X
authors.lastname: Qian
mesh_terms: D003124:Colorimetry; D003300:Copper / Q000032:analysis*; D004566:Electrodes; D005456:Fluorescent Dyes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D053644:Naphthalimides / Q000138:chemical synthesis / Q000737:chemistry*; D011522:Protons; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry
chemical_list: C540206:4,5-diamino-1,8-naphthalimide; D005456:Fluorescent Dyes; D053644:Naphthalimides; D011522:Protons; D012996:Solutions; D014867:Water; D003300:Copper