Binding interaction of bioactive imidazole with bovine serum albumin--a mechanistic investigation

Interaction of fluorescent sensor with superparamagnetic iron oxide nanoparticles

To sense superparamagnetic iron oxides (Fe2O3 and Fe3O4) nanocrystals a sensitive bioactive phenanthroimidazole based fluorescent molecule, 2-(4-fluorophenyl)-1-phenyl-1H-phenanthro [9,10-d] imidazole has been designed and synthesized. Electronic spectral studies show that phenanthroimidazole is bound to the surface of iron oxide semiconductors. Fluorescent enhancement has been explained on the basis of photo-induced electron transfer (PET) mechanism and apparent binding constants have been deduced. Binding of phenanthroimidazole with iron oxide nanoparticles lowers the HOMO and LUMO energy levels of phenanthroimidazole molecule. Chemical affinity between the nitrogen atom of the phenanthroimidazole and Fe(2+) and Fe(3+) ions on the surface of the nano-oxide may result in strong binding of the phenanthroimidazole derivative with the nanoparticles. The electron injection from the photoexcited phenanthroimidazole to the iron oxides conduction band explains the enhanced fluorescence.

Binding interaction of 1-(4-methybenzyl)-2-p-tolyl-1H-benzo[d]imidazole with bovine serum albumin

A promising benzimidazole derivative 1-(4-methybenzyl)-2-p-tolyl-1H-benzo[d]imidazole (MBTBI) has been synthesized and characterized by single crystal XRD, NMR, mass and IR spectral techniques. The mutual interaction of this benzimidazole derivative (MBTBI) with bovine serum albumin (BSA) was investigated using solution spectral studies. The fluorescence quenching mechanism of BSA by MBTBI was analyzed and the binding constant has been calculated. The binding distance between these two was obtained based on the theory of Forester's non-radiation energy transfer (FRET). The effect of some common ions on the binding constant was also examined.

Optical properties of organic nonlinear optical crystal--a combined experimental and theoretical study

The optical properties of the synthesized imidazole derivative, 1-(4-methoxyphenyl)-4,5-diphenyl-2-styryl-1H-imidazole, has been studied both experimentally and theoretically. Fluorescence enhancement have been found in the presence of transition metal ions and this may result from the suppression of radiationless transitions from the n-π* state in the chemosensors. Quantum chemical calculations of heat of formation, optimized geometry, NLO, HOMO-LUMO, MEP and NBO analysis of 1-(4-methoxyphenyl)-4,5-diphenyl-2-styryl-1H-imidazole (mpdsi) have been carried out by using density functional theory (DFT/B3LYP) method with 6-31G(d,p) as basis set. This chromophore possess more appropriate ratio of off-diagonal versus diagonal β tensorial component (r=β(xyy)/β(xxx)=-0.002) which reflects the inplane non-linearity anisotropy. Since they have largest μβ(0) value, the reported imidazole can be used as potential NLO material. The solvent effect on the absorption and fluorescence has been analyzed simultaneously.