Perovskite solar cells (PSCs) have emerged as a transformative photovoltaic technology, combining high power-conversion efficiencies with inexpensive, solution-based processing. However, their intrinsic instability and incomplete optical absorption currently hinder their widespread application. The integration of quantum dots (QDs) into PSCs has arisen as a promising strategy to address these limitations. By broadening the absorption spectrum, passivating defects, and facilitating charge transport, QDs can push single-junction PSC efficiencies to similar to 26% while improving long-term stability. This review surveys recent progress in QDPSCs systems, covering QDs synthesis and incorporation methods, device architectures, and optoelectronic enhancements. We discuss the multifaceted roles of QDs in defect passivation, moisture resistance, and interface engineering, and highlight concerns about scalability and lead toxicity. Finally, we outline future directions such as lead-free QDs, tandem cell designs, and scalable manufacturing to position QD-enhanced PSCs as next-generation photovoltaic candidates.
Bloch surface waves (BSWs) in periodic multilayer photonic crystals (PCs) were excited using a 635-nm laser for testosterone hormone detection employing the Kretschmann-Raether configuration. A 24-layer ZrO2-SiO2 PC served as the key dielectric sensing medium for the evanescent field interaction with testosterone molecules in blood plasma. Although SiO2 does not bind strongly to testosterone, it provides the necessary low-index component to achieve high contrast with ZrO2. The layer combinations are ideal for low optical loss in biosensing. A 20-mu L mixture of phosphate buffered saline, testosterone, and blood plasma with the testosterone concentrations of 0.5, 1, 10, 100, and 200 mM were poured over the PC surface. The acceptable viscosity of this mixture helps adhere the BSW-based sensor to the BK7 prism coupler surface used in the experiment. The results of polarized reflected transverse magnetic waves indicate strong dependence on the angular shift. The lowest concentration (of 0.5 mM) was detected at an angle of approximately 51.2 degrees, while the highest concentration (of 200 mM) was spotted at 51.7 degrees. For concentrations < 10 mM, the sensitivity of the studied BSW-based sensor was found to be nonlinear with the angular shift; higher concentrations, however, showed this feature to be linear.
The effect of seed layer thickness on the optical and electrical properties of ZnO nanorods (NRs) for fast-response UV photodetector applications was investigated. Vertically aligned ZnO NRs were grown via a hydrothermal method using seed layers with various thicknesses ranging from 350 nm to 550 nm. FESEM characterization revealed that the synthesized ZnO NRs had average diameters of 71 - 175 nm and lengths of 1.3 - 2 mu m. UV-Vis spectra indicated that the sample with the thinnest seed layer (350 nm), which exhibited a higher aspect ratio, showed enhanced absorption in the UV region. p-n heterojunction photodetectors (PDs) based on the synthesized ZnO NRs were fabricated, and their I-V and I-t characteristics were evaluated. The results demonstrated that optimizing the seed layer thickness in accordance with the UV wavelength significantly improves the photodetector's responsivity, sensitivity, and quantum efficiency, while also achieving remarkably fast response and recovery times. These findings highlight the critical role of structural tuning in enabling high-performance, fast-response UV photodetectors.
Nano herbal therapeutics combine nanotechnology with herbal medicine to overcome challenges like poor bioavailability and instability of phytochemicals. These formulations enhance efficacy, safety, and patient compliance compared to conventional herbal and synthetic nanoparticle systems. Plant-derived nanoparticles (PDNPs) offer benefits including improved cellular uptake, low toxicity, eco-friendliness, and costeffectiveness. Several nano-formulated herbal compounds have shown promising outcomes in preclinical and clinical studies, especially in cancer, inflammation, and metabolic disorders. This review highlights the pharmacokinetics, pharmacology, and therapeutic potential of nano-herbal systems while comparing PDNPs to synthetic counterparts. We also explore their mechanisms of action, molecular signaling pathways, and roles in targeted delivery. Additionally, the review addresses challenges such as formulation stability, large-scale production, regulatory gaps, and long-term toxicity. A systematic literature review was conducted using databases like PubMed, Scopus, and Web of Science. Emerging tools such as AI-assisted formulation and biodegradable carriers are discussed as future directions. The integration of nanotechnology and herbal medicine presents a transformative approach to disease treatment. However, regulatory standardization, environmental safety, and ethical commercialization remain critical for clinical translation.
Antibacterial polymeric nanofibers derived from PAN nanofibers exhibit remarkable promise for a variety of applications in the biomedical field. In this study, we explored the incorporation of zinc oxide and copper oxide nanoparticles into PAN/ZnO/CuO nanofibers, which were meticulously fabricated using the electrospinning technique complemented by an ex-situ generation method. The structural properties of the PAN/ZnO/CuO nanofibers were characterized through XRD analysis, which confirmed a significant interaction between the ZnO/CuO nanoparticles and the electrospun PAN matrix. Additionally, FE-SEM and AFM imaging provided compelling visual evidence that the ZnO/CuO nanoparticles are uniformly distributed throughout the PAN nanofiber network, indicating a well-integrated composite structure. To evaluate their potential for clinical use, we rigorously tested the antibacterial efficacy of the PAN/ZnO/CuO nanofibers against a range of bacterial strains commonly found in hospital environments. The results were promising, revealing that these composite nanofibers exhibit a pronounced antibacterial effect against several pathogens, including Salmonella, Shigella, Escherichia coli, Streptococcus pneumoniae, and Staphylococcus aureus. Such findings suggest that these advanced nanofibers could play a crucial role in enhancing infection control measures in medical settings.
