ABSTRACT
A new probe, 3-[(3-benzyloxypyridin-2-ylimino)methyl]-2-hydroxy-5-methylbenzaldehyde (1-H) behaves as a highly selective fluorescent pH sensor in a Britton-Robinson buffer at 25 °C. The pH titrations show a 250-fold increase in fluorescence intensity within the pH range of 4.2 to 8.3 with a pK(a) value of 6.63 which is valuable for studying many of the biological organelles.
Subject(s)
Fluorescent Dyes/chemistry , Schiff Bases/chemistry , Crystallography, X-Ray , Hydrogen-Ion Concentration , Models, Molecular , Molecular Structure , Quantum Theory , StereoisomerismABSTRACT
A new 2,6-bis(5,6-dihydrobenzo[4,5]imidazo[1,2-c]quinazolin-6-yl)-4-methylphenol (1) serves as a highly selective and sensitive fluorescent probe for Zn(2+) in a HEPES buffer (50 mM, DMSO:water = 1:9 (v/v), pH = 7.2) at 25 °C. The increase in fluorescence in the presence of Zn(2+) is accounted for by the formation of dinuclear Zn(2+) complex [Zn(2)(C(35)H(25)N(6)O)(OH)(NO(3))(2)(H(2)O)] (2), characterized by X-ray crystallography. The fluorescence quantum yield of the chemosensor 1 is only 0.019, and it increases more than 12-fold (0.237) in the presence of 2 equiv of the zinc ion. Interestingly, the introduction of other metal ions causes the fluorescence intensity to be either unchanged or weakened. By incubation of cultured living cells (A375 and HT-29) with the chemosensor 1, intracellular Zn(2+) concentrations could be monitored through selective fluorescence chemosensing.
Subject(s)
Benzimidazoles/chemical synthesis , Cresols/chemical synthesis , Fluorescent Dyes/chemical synthesis , Quinazolines/chemical synthesis , Spectrometry, Fluorescence/methods , Zinc/chemistry , Buffers , Cations, Divalent , Cell Line, Tumor , Crystallography, X-Ray , HT29 Cells/pathology , HT29 Cells/ultrastructure , Humans , Hydrogen-Ion Concentration , Melanoma/pathology , Melanoma/ultrastructureABSTRACT
{[Cu(2)(H(2)L)(OH)(H(2)O)].(ClO(4))(2)(H(2)O)} (1) serves as a selective azide ion fluorescent sensor in aqueous medium. 1 binds with N(3)(-) to give [Cu(6)(HL)(2)(mu(1,1)-N(3))(6)] (2) which imposes rigidity and decreases the non-radiative decay of the excited state to give rise to fluorescent enhancement. 1 is highly selective over other various anions in aqueous medium.
