Folic acid-functionalized L-cys/ZnS:O nanoparticles for homologous targeting and photodynamic therapy of tumor cells

The combination of photodynamic therapy (PDT) and fluorescence imaging provides a promising approach to theranostics. However, traditional photosensitizers (PSs) have low water solubility and lack active targeting ability. Our ingenious design used L-cys/ZnS:O (LZS) nanoparticles (NPs) modified with folic acid (FA), allowing them to easily enter tumor cells and accurately gather around the nucleus of cancer cells. L-Cysteine were used as intermediates, ZnS:O quantum dots and FA could be connected by a solid-state method and a coupling reaction. In doing so, the cytotoxicity of LZS NPs was further reduced, while the hydrophilicity and dispersibility were improved. Moreover, the as-synthesized FA@LZS NPs had a higher generation of reactive oxygen species (ROS) than commercial Ce6, and they killed HepG2 cells specifically in vitro. These findings give a clear way for the development of advanced PSs with homologous labeling functions. A template for NPs or other fluorophores modified by targeting groups is also provided.

Hydrothermal construction of WO3.0.33H2O/g-C3N4 nanocomposites with enhanced adsorption and photocatalytic activity

Tungsten trioxide has attracted extensive attention for photocatalytic applications owing to its unique structure and intrinsic merits; however, small specific surface area and rapid electron-hole recombination still limit its adsorption...

Heterojunction interface of zinc oxide and zinc sulfide promoting reactive molecules activation and carrier separation toward efficient photocatalysis

Heterojunction photocatalysts, which can alleviate the low carrier separation efficiency and insufficient light absorption capacity of a single catalyst, have received widespread attention. However, the specific interfacial structure of the heterojunction and its effect on the photocatalytic reaction is still unclear. Herein, a battery of zinc oxide/zinc sulfide (ZnO@ZnS) heterojunction microspheres with different degrees of sulfuration were successfully constructed via a facile hydrothermal method. The as-prepared photocatalysts shown decent aerobic nitric oxide (NO) oxidation performance under visible light irradiation, and the results of various characterization techniques illustrated that the superior photoactivity could be ascribed to the spatial separation of photoinduced electron-hole pairs due to the synergy of the internal electric field and the band offset. More importantly, density functional theory (DFT) calculations revealed that the heterojunction interface can significantly promote the generation of reactive oxygen species (ROS) and NO⁺ reaction intermediates and thus accelerate the photocatalytic reaction. Finally, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) technology was used to time-dependently monitor the NO oxidation process, revealing the photocatalytic mechanism. This work investigated the role of the heterojunction interface in the gas-phase catalytic reaction, broadening the practical application of the ZnO@ZnS heterojunction.