Sonochemically synthesized black phosphorus nanoparticles: a promising candidate for piezocatalytic antibacterial activity with enhanced dielectric properties.

The drawbacks inherent to traditional antibacterial therapies, coupled with the escalating prevalence of multi-drug resistant (MDR) microorganisms, have prompted the imperative need for novel antibacterial strategies. Accordingly, the emerging field of piezocatalysis in semiconductors harnesses mechanical stress to drive chemical reactions by utilizing piezo-generated free charge carriers, presenting a promising technology. To the best of our knowledge, this study is the first to provide a comprehensive overview of the eradication of pathogenic S. aureus bacteria using few-layer black phosphorus (SCBP) piezo catalyst under mechanical stimuli, along with the exploration of temperature dependent dielectric properties. The synthesis of the piezo catalysts involved a one-step cost-effective sonochemical method, and its structural, morphological, elemental, optical, and overall polarization properties were thoroughly characterized and compared with the traditional method-derived product (TABP). The synthesis-introduced defects, reduced crystalline diameters, modified bandgap (1.76 eV), nanoparticle aggregation, photoluminescence quenching, along with interfacial polarization, synergistically contribute to SCBP's exceptional dielectric response (4.596 × 107 @40 Hz), which in turn enhanced the piezocatalytic activity. When subjected to soft ultrasound stimulation at 15 kHz, the piezo catalyst SCBP demonstrated significant ROS-mediated antibacterial activity, resulting in a ∼94.7% mortality rate within 40 minutes. The impact of this study extends to cost-effective energy storage devices and advances in antibacterial therapy, opening new dimensions in both fields.

Effect of Homeopathic Dilutions of Cuprum Arsenicosum on the Electrical Properties of Poly(Vinylidene Fluoride-Co-Hexafluoropropylene).

BACKGROUND: We report the effects of nanoparticles in homeopathic preparations of copper salts on the electrical properties of polymer film. Previous work showed that the incorporation of metal-derived homeopathic medicines increases the dielectric constant and alternating current (AC) conductivity of an electroactive polymer film that is commonly used as a capacitor in the electronic industry.We report here the effect of dilution of one homeopathic medicine, Cuprum arsenicosum (CuAs), at 200C potency on the electrical properties of the polymer film of poly(vinylidene fluoride-co-hexafluoropropylene). METHODS: CuAs 200c was incorporated in the film by the solution casting method. The electrical characteristics were measured at different frequencies using an inductance, capacitance, and resistance meter. Fourier transform infrared spectroscopy (FTIR) was performed to detect phase change in the polymer film due to the incorporation of CuAs. Morphology and particle size were studied using field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) spectroscopy. RESULTS: At 10 kHz frequency, both dielectric constant and AC conductivity increased approximately 18 times for the polymer film when incorporated with 2 mL CuAs at 200C potency. FTIR indicated the increase in conducting phase, while FESEM and EDX confirmed the presence of spherical CuAs particles. CONCLUSION: The incorporation of CuAs in the electroactive polymer film enhances the conductivity and dielectric constant. We conclude that these changes arise from the change in phase of the polymer film, and because of the presence of two different metals that affects the interfacial polarization.