The undertaken study describes synthesis of air resistant copper nanoparticles (Cu NPs) in an aqueous phase using sodium borohydride as a reducing agent via chemical reduction method. The hydrosol has resistant to oxidation by atmospheric oxygen for several days. The air stability was induced by capping Cu NPs with anionic surfactant "sodium dodecyl sulfate (SDS)". Ascorbic acid was used as an antioxidant. These Cu NPs were characterized by ultraviolet-visible (UV-VIS) spectroscopy, which contributed towards the understanding of surface plasmon resonance (SPR) generation and optical behavior of Cu NPs. It was used as an optical tracer for size control and confirmation of Cu NPs and was found to be affected by various parameters like reaction time, pH, concentration of copper sulfate and the surfactant SDS. SPR peaks were found to shift from 597 to 569 nm, while apparent color changes from yellow to brick red. Further characterization studies were carried out by using fourier transform infrared (FT-IR) spectroscopy to investigate the co-ordination between Cu NPs and SDS. X-ray diffraction (XRD) was used for phase purity of Cu NPs. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) were used the size and morphological characterization. The average size of the Cu NPs was found to be 15 nm in diameter with an average height of 14 nm. The Cu NPs showed excellent catalytic activity in the reductive degradation of Eosin B (EB) dye in just 16 sec of reaction time and maintained their catalytic activity when reused multiple times. The degradation rate was found to follow first order reaction kinetics with the EB degradation. The Cu NPs enhanced the rate of EB degradation 30 times more than the control test. Copper was found an attractive catalyst in the nanosize regimes. The Cu NPs are more economical as compared to noble metals. The Cu NPs are expected to be suitable alternative and play an imperative role in the fields of catalysis and environmental remediation.

BackgroundNanotechnology has potential future for enhancing therapeutic efficacy and reducing the unwanted effects of herbal drugs. The biological research on Euphorbia species has been supported by the use of some plants in traditional medicines. Many species of Euphorbia have been reported as having strong sedative and analgesic effects. In the present research work gold nanoparticles of Euphorbia milii methanolic extract (Au-EM) were synthesized, characterized and tested for antinociceptive, muscle relaxant and sedative activities.MethodsAu-EM was prepared by stirring 1 mM warm trihydrated tetrachloroaurate solution with E. milii methanolic extract without using any external reducing agents. The gold nanoparticles were characterized by UV-Visible spectroscopy, infrared spectrophotometery, atomic force microscopy and scanning electron microscopy while their stability was evaluated against varying pH and different volumes of sodium chloride (NaCl). The metal sensing capacity of Au-EM was tested towards cobalt, copper, lead, mercury and nickel. Au-EM was evaluated in BALB/c mice at a dose of 10 and 20 mg/kg for antinociceptive, muscle relaxant and sedative activities in comparison with the crude E. milii methanolic extract.ResultsAu-EM showed remarkable stability in different NaCl and pH solutions. Au-EM produced significant (P < 0.01) antinociceptive effect at doses of 10 and 20 mg/kg as compared to the crude E. milii methanolic extract. In the rotarod test, Au-EM showed significant muscle relaxant effect at 10 mg/kg (P < 0.05) and 20 mg/kg (P < 0.01) after 30, 60 and 90 min. In an open field test significant sedative effect (P < 0.05) of Au-EM was observed at 10 and 20 mg/kg. Moreover significant detection sensitivity was demonstrated towards all the tested heavy metals.ConclusionsThese results concluded that the gold nanoparticles improved the potency of E. milii methanolic extract and exhibited significant analgesic, muscle relaxant and sedative properties. The significant metals sensing ability and enhanced stability in different NaCl and pH solutions may enable us to explore different formulations of E. milii gold nanoparticles for potentially effective and safe nano-herbal therapy.

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