Comments on “Photophysics of rhodamine B in the nanosized water droplets: A concentration dependence study”

Two new layered metal chalcogenide frameworks as photocatalysts for highly efficient and selective dye degradation

Dye photodegradation is an important research topic, and great efforts have been made to target the photocatalysts with highly efficient and selective performance. Reported here are two layered anion chalcogenide frameworks with semiconducting properties combined with highly open interlayer spaces, which are used as efficient photocatalysts to show excellent size and charge selectivity towards organic dye molecules. In addition, the organic templates inside the chalcogenide frameworks are exchanged via an ion-exchange process, and the resulting host frameworks with much looser internal spaces play significant roles in improving the photocatalytic activity.

Effect of Environment on Protoporphyrin IX: Absorbance, Fluorescence and Nonlinear Optical Properties

The present study investiaged the enhancement of nonlinear optical properties of Protoporphyrin IX in photodynamic therapy using nano-droplet. To this end; absorbance, fluorescence, and nonlinear optical properties of Protoporphyrin IX were examined and results showed that dye aggregation and dielectric constant of solvent could change absorbance and fluorescence spectra. According to quantum mechanical perturbation theory, dipole moment of Protoporphyrin IX in solutions of water-ethanol was extracted. The values of nonlinear absorption and nonlinear refractive index of Protoporphyrin IX in AOT/Toluene/H₂O were also reproted to be larger than aqueous solutions, due to polarity reduction of solvent as well as discount of Protoporphyrin IX aggregation in AOT/Toluene/H₂O. Furthermore, the effect of cell culture media on the nonlinear optical properties of Protoporphyrin IX was analyzed and the results were compared with those of water. The photon correlation spectroscopy of solution also showed a growth in dye-droplet aggregation following the increase of Protoporphyrin IX concentration.