Synthesis, characterization and protein-association of dicyanomethylene squaraine dyes
作者:Tiago D. Martins、Marlene L. Pacheco、Renato E. Boto、Paulo Almeida、José Paulo S. Farinha、Lucinda V. Reis
DOI:10.1016/j.dyepig.2017.07.070
日期:2017.12
We prepared several new dicyanomethylene squaraine dyes derived from indolenine, benzothiazole and benzoselenazole, with different substituent groups. All the obtained dyes display intense and narrow absorption bands and bright fluorescence emission in the Vis/NIR region (665-716 nm) when dissolved in organic solvents, especially for the unsymmetrical dyes containing sulphur and selenium atoms.The use of synthesized squaraine dyes as fluorescent probes for detection of bovine serum albumin (BSA) and human serum albumin (HSA) was explored in Tris-HCI buffer solutions. We observed that all the dyes are non-emissive in buffer solution but become fluorescent in the presence of BSA or HSA proteins, with the emission intensity increasing proportionally to the protein concentration (0.00-1.22 mu M). The most pronounced effect was observed for the symmetrical squaraine having two moieties of indolenine. (C) 2017 Elsevier Ltd. All rights reserved.
New Synthetic Approach to Aminosquarylium Cyanine Dyes
作者:P. F. Santos、L. V. Reis、J. P. Serrano、P. Almeida
DOI:10.1055/s-2002-34226
日期:——
A novel synthesis of aminosquarylium cyaninedyes, based on the methylation of readily available squarylium dyes with methyl triflate, followed by nucleophilic substitution with appropriate aliphatic amines, was disclosed. By this procedure several new aminosquarylium cyaninedyes bearing benzothiazole, benzoselenazole and quinoline nuclei were prepared.
The synthesis and spectroscopic characterisation of some representative N-alkyl-substituted quaternaryammoniumsalts derived from benzothiazole, benzoxazole, benzo-selenazole, indole and quinoline are described. These heterocyclic salts, bearing an activated methyl group in the 2-position in relation to the nitrogen atom and N-methyl, -pentyl, -hexyl and -decyl chains, are typical precursors of cyanine