Dye Modified Phenylenediamine Oligomers: Theoretical Studies on Drug Binding for Their Potential Application in Drug Sensors.

The present work reports, for the first time, synthesis of dye incorporated o-phenylenediamine (OBB) with a view to obtain a conjugated oligomer with enhanced functionality. The structure was confirmed by IR studies, while the electronic transitions were confirmed by UV visible studies. The dye modified oligomer showed one order higher fluorescence intensity than the pristine Bismarck Brown (BB) dye. Confocal imaging showed red emission which could be utilized in near infra-red imaging. Density functional theory (DFT) studies were carried out to predict the theoretical properties of the oligomers. The energies of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital orbital were computed to explore how the HOMO energies of the reactants initiated the electronic interactions between them. The interaction energies were correlated to conjugation/hyper conjugation stabilization energies of the natural bond orbitals (NBO) via the DFT method using the B3LYP functional with the 6-311G(d) basis set on Gaussian 09 software. Drug binding was evaluated through simulation of interaction energy, (ΔEA-x) with drugs such as captopril, propranolol, thiazide, and fentanyl. The results predicted that the oligomer could be developed into a fentanyl drug sensor.

Highly Efficient Photocatalytic Degradation of Amido Black 10B Dye Using Polycarbazole-Decorated TiO2 Nanohybrids.

The present study reports the synthesis of polycarbazole (PCz)-decorated TiO2 nanohybrids via in situ chemical polymerization of carbazole monomers in TiO2 dispersions. The ratio of the polymer in the nanohybrid varied between 0.5 and 2 wt %. The synthesized nanohybrids were characterized using infrared and diffuse reflectance spectroscopies, whereas the morphology was analyzed using X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. XRD revealed changes in the peak corresponding to the d(001) plane of TiO2 owing to the interaction between the two components. TEM confirmed the formation of PCz-decorated nanohybrids. Amido Black 10B (AB-10B) was chosen as a model dye for the degradation studies. Sonophotocatalytic degradation of the dye was studied by varying the catalyst and dye concentrations. Results showed that PCz/TiO2 nanohybrids exhibited a complete degradation of AB-10B dye within a short span of 60-90 min, which was faster than pure TiO2 and the reported decorated TiO2 nanohybrids synthesized by other authors. The degraded dye fragments were identified using liquid chromatography-mass spectrometry (LCMS). By varying the loading of PCz in TiO2, the nanohybrids could be tuned to achieve visible light-driven degradation.