Biofabrication of copper oxide nanoparticles (CuO-NPs) of a desired size remains a significant challenge. In this report, CuO-NPs were fabricated by treating 10mM copper nitrate with Andean blackberry fruit (ABF) and leaf (ABL); and evaluated its antioxidant activity. As-prepared NPs characterization were determined by UV–visible spectrophotometry, Dynamic Light Scattering (DLS), transmission electron microscopy (TEM) with selected area electron diffraction (SAED) and X-ray diffraction (XRD) analysis. UV–visible spectroscopy showed an electronic excitonic transition at 250–255nm clearly reveals the formation of ABF and ABL CuO-NPs. DLS analysis demonstrated mean diameter of ABF CuO-NPs (43.3nm) smaller than ABL CuO-NPs (52.5nm). TEM with SAED confirmed the CuO-NPs are spherical and of partial crystalline nature. Furthermore, the antioxidant efficacy of ABF CuO-NPs showed 89.02%, 1mM whereas ABL CuO-NPs 75.92%, 1mM against 1,1-diphenyl-2-picrylhydrazyl. From the results obtained it is suggested that green CuO-NPs could be used effectively in future biomedical concerns

In this work, we analyzed the advantages of using silver nanoparticles (AgNPs) synthesized with natural extracts in ultraviolet–visible spectroscopy (UV-Vis) protective cream. The photodegradation properties of the new UV-Vis protective milk show an increase in its absorption band compared to AgNP-free cream. Previous to the study of the AgNPs mixed within the body milk, we studied the optical UV-Vis properties of extracts at different collection times, as they can influence the spectral range of UV-Vis absorption of the hybrid compound (AgNPs + natural extract). Shape and size of the AgNPs differs from the type of reducing agent as well as the concentration of silver nitrate used. We also compared the cytotoxicity in cell lines and the antibacterial effect of the AgNPs without and with organic coating. All these studies showed that we obtained hybrid sun-protective body milk with a high degree of solar protection and with low cytotoxicity at a cellular level, thus improving its protective properties. The synthetized hybrid compound could be a possible cost-affordable alternative for the market.

In this article, silver-doped titanium dioxide nanoparticles (Ag/TiO ₂ NPs) were synthesized in an ecologically and economically favorable way using rambutan ( Nephelium lappaceum L.) peel extracts along with the study of its photocatalytic activity on methylene blue (MB) dye and antioxidant efficacy against 1,1-diphenyl-2-picrylhydrazyl (DPPH·). A wide range of analytical techniques including UV-vis spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy analysis were performed to ascertain the synthesis of Ag/TiO ₂ NPs. The synthesized Ag/TiO ₂ NPs enhanced the photocatalytic degradation of MB (81.6%, k=0.002495 min ^-1 ) under direct solar light irradiation. The results showed that discarded agricultural waste as rambutan peel can be utilized as natural bioreductant in future materials science applications.