carbocyanines and carbazole

A hybrid carbazole-hemicyanine dye (Cac) has been developed as a novel colorimetric and ratiometric fluorescent sensor for cyanide detection. Upon treatment with cyanide, Cac displayed a remarkable fluorescence ratiometric response, with the emission wavelength displaying a very large emission shift (214 nm). The detection of cyanide was performed via the nucleophilic addition of cyanide anion to the indolium group of the sensor, which resulted in the blocking of the intramolecular charge transfer (ICT) process in the sensor, inducing a ratiometric fluorescence change and simultaneously an obvious color change. Furthermore, competitive anions did not showed any significant changes both in color and emission intensity ratio (I381/I595), indicating the high selectivity of the sensor to CN(-).

Topics: Anions; Carbazoles; Carbocyanines; Colorimetry; Cyanides; Fluorescent Dyes; Spectrometry, Fluorescence

Many organic ligands were synthesized to recognize G-quadruplexes. However, different kinds of G-quadruplexes (G4s) possess different structures and functions. Therefore, selective recognition of certain types of G4s is important for the study of G4s. In this paper, a novel cyanine dye, 3-(2-(4-vinylpyridine))-6-(2-((1-(4-sulfobutyl))-3,3-dimethyl-2-vinylbenz[e]indole)-9-ethyl-carbazole (9E PBIC), composed of benzindole and carbazole was designed and synthesised. The studies on UV-vis and fluorescence properties of the dye with different DNA forms showed that the dye exhibits almost no fluorescence under aqueous buffer conditions, but it increased over 100 fold in the presence of c-myc G4 and 10-30 fold in the presence of other G4s, while little in the presence of single/double-stranded DNA, indicating that it has excellent selectivity to c-myc 2345 G4. For the binding studies the dye is interacted with the c-myc 2345 G-quadruplex by using the end-stack binding model. It can be said that the dye is an excellent targeting fluorescent probe for c-myc G-quadruplexes.

Topics: Carbazoles; Carbocyanines; Chemistry Techniques, Analytical; Coloring Agents; Drug Delivery Systems; Fluorescent Dyes; G-Quadruplexes; Molecular Structure; Proto-Oncogene Proteins c-myc

Novel biocompatible cyanines show not only a very large two-photon cross-section of up to 5130 GM at 910 nm in aqueous medium for high-contrast and -brightness two-photon fluorescence live cell imaging but also highly selective subcellular localization properties including localization of mitochondria and lysosomes.

Topics: Carbazoles; Carbocyanines; Cell Line; Fluorescent Dyes; Humans; Lysosomes; Microscopy, Confocal; Mitochondria; Photons

Based on cyanine dye probe oxazole yellow (YO) and Cy(3), a series of novel styryl cyanine dyes were designed and synthesized. Carbazole was inserted into the structures of YO and Cy(3) to act as a bridge to link the benzoxazole and indole group. This modification resulted in a novel kind of benzoxazole indole styryl cyanine dye with a carbazole-bridged chain. The dyes were characterized by (1)HNMR and MS. The spectra of the novel dyes were also performed and the results showed that the maximum emission wavelength of the carbazole styryl cyanine dye was shifted red, the Stokes shift increased and the fluorescence intensity enhanced compared with those of YO and Cy(3). These results indicated that the novel dye could be used as an excellent fluorescent probe in biological labeling.

Topics: Animals; Benzoxazoles; Carbazoles; Carbocyanines; Cattle; Chemistry Techniques, Synthetic; Fluorescent Dyes; Quinolines; Serum Albumin, Bovine; Spectrometry, Fluorescence

Topics: Carbazoles; Carbocyanines; Fluorescent Dyes; HeLa Cells; Humans; Intracellular Space; Microscopy, Fluorescence; Nonlinear Dynamics; Staining and Labeling