meso-Substituted Carbocyanines as Effective Spectral-Fluorescent and Photochemical Probes for Structurally Organized Systems Based on Macromolecules

Photonics of Some Monomethine Cyanine Dyes in Solutions and in Complexes with Biomolecules

“…For aqueous solutions, taking into account the spin-statistical factor of the interaction of a triplet molecule with triplet molecular oxygen (1/9), k qO2 should be equal to 1/9 k dif ~3 × 10 9 mol −1 L s −1 . This decrease is because of the fact that the complexation of polymethine dyes with biomacromolecules probably leads to partial shielding of dye ligands, which leads to hindered access of quencher molecules (in particular, dissolved oxygen) to the T state of the dyes and a decrease in the quenching rate constant [ 70 , 71 , 72 ].…”

Molecular docking of cyanine and squarylium dyes with SARS‐CoV‐2 proteases NSP3, NSP5 and NSP12

“…When using dyes for the spectral detection of proteins, an important role is played by the change in the spectral‐fluorescent properties of the dyes upon complexation. A sharp growth of fluorescence is observed for meso ‐substituted carbocyanines (trimethine cyanines) due to a shift in the dynamic cis – trans equilibrium, which allows detection of very low concentrations of biomolecules when the dyes are used as fluorescent probes [7,8,23,24].…”

“…Symmetric mono‐, tri‐, penta‐, and heptamethine cyanine dyes, both cationic and anionic (having negatively charged sulfonate groups) with various heterocycles (benzimidazolyl, benzothiazolyl, benzoxazolyl) and substituents in heterocycles, were studied. Trimethine cyanines (carbocyanines) also had various substituents in the meso position of the polymethine chain (CH 3 , C 2 H 5 , CH 3 O, CH 3 S, Cl), since meso ‐substituted thiacarbocyanines were previously characterized as effective probes for biomacromolecules [7,8,23,24]. Also studied were squarylium dyes, including squarylium indo‐ and thiacyanines with anionic sulfonate groups.…”

“…In this respect, cyanine dyes represent an attractive class of fluorescent probes and markers whose main advantages lie in the high extinction coefficients, absorption and emission in UV to NIR spectral ranges covering the optical window for biological samples, and their photophysical and photochemical properties, which depend on the molecular environment [6]. Furthermore, cyanine dyes (and related squarylium dyes) are capable of noncovalent interaction with biomolecules with fluorescence growth, which creates the prerequisites for their use as probes in biomolecular systems [7,8]. The variety of structures and properties of cyanine dyes of different classes (which contain a polymethine chain of different length, different terminal heterocycles and substituents) requires molecular modeling in silico in preliminary screening the compounds.…”

Polymethine Dyes as Probes for Detecting the SARS-COV-2 Coronavirus: In silico Molecular Docking Study

“…They possess high extinction coefficients, absorption, and emission in the long-wavelength region, covering the optical transparency window of biological samples and tissues; in addition, their photophysical and photochemical properties depend on the molecular environment [ 1 ]. Cyanine and squarylium dyes can interact with biomolecules to form noncovalent complexes to increase the fluorescence, so that they may be used as probes in systems containing biomolecules [ 2 , 3 ]. The dyes (including cyanine) are considered as spectral-fluorescent probes to study various viruses [ 4 ].…”