There are numerous studies reported on the usage of the sapindus emarginatus (SE) fruit in cancer and other treatments in the past few years. In this study, crude SE fruit extract was prepared and it was further used to synthesis gold nanoparticles (Au Nps). The synthesized Au Nps were left embedded in the SE fruit extract. The Au Nps embedded in the SE fruit extract (SE-Au Nps) were characterized using UV-Visiable Spectroscopy, Centrifugal Particle Size analyzer (CPS), Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). MTT assay was carried out for both SE fruit extract and SE-Au Nps on MCF7 breast cancer cell line and thus compared. The UV-Visible Absorbance for the SE-Au Nps was obtained at 543 nm. The centrifugal particle size analysis of the Au Nps embedded in SE fruit extract showed the size of the nanoparticles to be widely varying with higher fraction of particles between the size ranges of 15 to 20 nm. The morphology of the Au Nps embedded in SE fruit extract was observed using SEM. The presence of Au Nps in SE fruit extract was confirmed using FTIR. The results of the MTT assay on MCF7 breast cancer cell line proved that the % cell viability was less for SE-Au Nps than that of the SE fruit extract alone. Thus, the antiproliferative activity of the SE fruit extract was significantly enhanced by embedding it with Au Nps and it can be effectively used in therapeutic applications after further studies.

Due to its physicochemical properties, nanoparticles titanium dioxide (nTiO₂) is being put into mass production and widespread applications, which inevitably results in their increasing exposure to the water body. After it entering the water body, the chemical properties of nTiO₂ can be influenced by ion compositions, ion strength and pH, which affects their ecological risk. Excess of ammonium (NH₄⁺) fertilizer has contaminated soil and water environments. In this paper, the Zeta potentials and hydrodynamic radius of nTiO₂ were studied in NH₄⁺ solution compared to those in Na⁺ solution. In addition, the sedimentation rate of nTiO₂ was also investigated. The experiment results show that high pH inhibits the sedimentation of nTiO₂. Moreover, NH₄⁺ increases the stability of nTiO₂ more than Na⁺ at the same IS, which was attributed the more negative Zeta potentials and the smaller hydraulic radius. Our results provide a theoretical basis for evaluating the ecological risk of nTiO₂ in aqueous solution containing NH₄⁺.