Engineered Oxide Nanoparticles Research Articles

Impact of GA3 encapsulated nanosilica on maize seed viability

The nanoparticles have the potential ability of the passing cell membrane because of their nano sizes. The SiO 2 nanoparticles are one of the major and frequently used engineered oxide nanoparticles. In present investigation, the potential effect of SiO 2 (10-20 nm) nanoparticles on maize seed viability were studied. We observed quick result of seed viability and also increase the seed viability percentage in presence of GA 3 loaded silica nanoparticles. Three concentration of (0.5, 0.2 and 0.1%) tetrazolium salts were also used for staining of living tissue. In the present experiment seeds conditioned in 150 pp GA 3 encapsulated nanosilica and tested in 0.5% TZ salt gave maximum viable seeds which was due to the increased availability of GA 3 and showed quick staining over 0.2% and 0.1% concentration. Among the varieties, var. Navin imbibed in 150 ppm GA 3 loaded nanosilica showed higher value of viable seed under 0.5% tetrazolium solution by better availability of GA 3 . Gibberellic acid enhances metabolic activity of seed by secretion of α-amylase enzyme which is important for quick staining of embryonic tissue.

Effect of oxide nanoparticles on the morphology and fluidity of phospholipid membranes and the role of hydrogen bonds

Engineered oxide nanoparticles (NPs) are widely applied in insulators, catalyzers, paints, cosmetic products, textiles and semiconductors. Their attachment on cell membrane may lead to cytotoxicity. The effects of Al2O3, Fe2O3, SiO2, TiO2 and ZnO NPs on membrane integrity and fluidity were studied using giant or small unilamellar vesicles in this study. Al2O3 and SiO2 NPs disrupted the oppositely charged membrane, indicating the important role of electrostatic attraction. However, Fe2O3, TiO2 and ZnO NPs did not cause serious membrane disruption as Al2O3 and SiO2 NPs. Membrane fluidity was evaluated by the generalized polarity (GP) values of Laurdan fluorescent emission. SiO2 NPs induce the membrane gelation of both positively and negatively charged membrane. Al2O3 and ZnO NPs induced the gelation of the oppositely charged membrane, but did not cause obvious membrane gelation to the like charged membrane. The phospholipid molecular structural changes after NP exposure were analyzed by Fourier transform infrared (FT-IR) spectroscopy. FT-IR spectra revealed the hydrogen bond formation between NPs and the carbonyl/phosphate groups of phospholipids. Al2O3 and SiO2 NPs showed strongest evidence of hydrogen bonding on their FT-IR spectra. It was consistent with the microscopic observation and fluorescent data that Al2O3 and SiO2 NPs caused more serious membrane disruption and gelation. This study on membrane damage provides further knowledge on the cytotoxicity of nanomaterials and the safety of NP application.

Effects of coated and non-coated ZnO nano particles on cucumber seedlings grown in gel chamber

ABSTRACTZinc oxide-engineered nanoparticles (ZnO ENPs) have received the most attention in recent years. This increasing interest has been directed towards studying the environmental fate and effects of ZnO ENPs on ecological terrestrial species. In this study, ZnO NPs were synthesized by atmospheric pressure solution evaporation method and were coated or uncoated with humic acid (HA). The root uptakes of uncoated and HA-coated ZnO NPs and zinc (Zn) were investigated by gel-grown cucumber. Two ZnO levels (1 and 200 µM) were applied in the form of coated (T3) and non-coated (T2) NPs or bulk particles (T1). The results showed that coating NPs by HA increases zeta potential of NPs and decreases their aggregation size due to the increase in the repulsion forces among the particles. Addition of 1 mgL−1 ZnO into gel chamber enhanced root and shoot biomass; however, the shoot growth was higher in the presence of NPs compared to its bulk counterpart. Moreover, greater phytotoxicity of ZnO from the source of NPs than bulk particles in shoot was observed. Scanning electron microscopy results showed a clear evidence of the penetration of NPs into root cells.

Fate of Silica Nanoparticles in Simulated Primary Wastewater Treatment

Through novel application of small-angle neutron scattering, we examined the fate of silica nanoparticles (SiO(2)NPs) during simulated primary wastewater treatment, by measuring, in real time, the colloidal behavior of SiO(2)NPs in wastewater (sewage). We examined the effects of surface functionality on SiO(2)NP fate in wastewater, by comparing both unfunctionalized (uncoated or "bare") SiO(2)NPs and SiO(2)NPs functionalized with a thin coating of a nonionic surfactant (Tween 20), which is widely used in personal care and household product formulations containing engineered oxide nanoparticles. Our results show new evidence that the surface functionality of SiO(2)NPs plays a crucial role in their flocculation and sedimentation behavior in wastewater, and thus the likely efficacy of their removal from the effluent stream during primary wastewater treatment. Uncoated SiO(2)NPs did not flocculate in wastewater over typical residence times for primary treatment. Conversely, surface-functionalized (Tween-coated) SiO(2)NPs underwent rapid flocculation in wastewater. Our results show that the surface-functionalized SiO(2)NPs are likely to be removed by sedimentation to sewage sludge (typically recycled to land), whereas uncoated SiO(2)NPs will continue through the effluent stream. While nanoparticle design is driven by use purpose, this study shows new potential for exploiting surface functionalization of nanoparticles to modify their environmental pathways.