The comparison of antibacterial activities of CsPbBr3 and ZnO nanoparticles

Effect of Yttrium doping on antibacterial and antioxidant property of LaTiO3

The advancement of multidrug-resistant bacterial strains and their adverse effects is one of the most significant global health issues. The perovskite nanomaterial with combined antioxidant and antibacterial activities in one molecule has the potential for improved therapeutic solutions. In this work, Yttrium-doped Lanthanum Titanate (LaTi1 -xYxO3, where x = 0, 0.05, and 0.1) was synthesized using auto combustion technique. Excellent crystalline structure with a tetragonal system is revealed by X-ray diffraction analysis (XRD). UV-Visible diffuse reflectance spectroscopy (UV-Vis DRS), Fourier transform infrared (FTIR), and photoluminescence (PL) were used to study its optical characteristics. The field emission scanning electron microscope (FE-SEM) shows rod-like pellet-shaped Yttrium-doped nanostructures, and the elements present were confirmed with the Energy Dispersive X-Ray Analysis (EDAX). Various concentrations of the synthesized materials were tested for antibacterial activity against Gram-positive (Staphylococcus aureus 902) and Gram-negative (E. coli 443) strains using the agar-well diffusion method with gentamicin antibiotic as a positive control. High antibacterial activity of 87.1% and 83.3% was shown by 10% Yttrium-doped LaTiO3 (LY(0.1)TO) at 500 mg/mL against both positive and negative stains, respectively. Moreover, the antioxidant properties of synthesized materials were assessed with IC50 values of 352.33 µg/mL, 458.055 µg/mL, and 440.163 µg/mL for samples LaTi1 - xYxO3, where x = 0, 0.05, and 0.1 respectively. The antibacterial and antioxidant capabilities of the proposed samples illustrate their applicability in various biomedical applications.

High-yield synthesis of CsPbBr3nanoparticles: diphenylphosphine as a reducing agent and its effect in Pb-seeding nucleation and growth

Based on the reported nucleation mechanisms for CsPbX₃and II-VI/IV-VI quantum dots, CsPbBr₃nanoparticles with a higher reaction-yield (up to 393% mass-increment) were synthetized by the hot-injection method. The introduction of diphenylphosphine (DPP) as a reducing agent improved nanoparticle nucleation and growth, giving out evidence for Pb-seeding in CsPbBr₃nanoparticles formation. Additionally, a clear influence of the DPP in a CsPbBr₃-Cs₄PbBr₆incomplete phase transformation was observed, marked by the appearance of several PbBr₂nanoparticles. This indicated the need for an improved ratio between the stabilizing agents and the precursors, due to the increased number of nucleation sites produced by DPP. The resulting CsPbBr₃nanoparticles showed high quality, as they displayed 70%-90% photoluminescence quantum yield; narrow size distribution with an average nanoparticle size of∼10 nm; and the characteristic cubic morphology reported in previous works. This increment in CsPbBr₃nanoparticles' reaction yield will contribute to making them a more attractive option for different optoelectronic applications.