Radebe, NThwala, MelusiCele, LMSikhwivhilu, LMusee, NShumbula, P2014-03-252014-03-252013-08Radebe, N., Thwala, M., Cele, L.M., Sikhwivhilu, L., Musee, N., and Shumbula, P. 2013. The stability of Ag and ZnO engineered nanoparticles in Hoagland's nutrient water: the role of particle size and morphology. In: First Human Capital Development Workshop for Nanotechnologies and Nanosciences Risk Assessment, Pretoria, CSIR Knowledge Commons, 13 August 2013http://hdl.handle.net/10204/7294First Human Capital Development Workshop for Nanotechnologies and Nanosciences Risk Assessment, Pretoria, CSIR Knowledge Commons, 13 August 2013The current study seeks to investigate the dissolution dynamics of silver (nAg) and zinc oxide (nZnO) engineered nanoparticles (ENPs), and how this affects their uptake by aquatic higher plants. First, the influence of particle size and morphology on the stability of nAg and nZnO in Hoagland’s nutrient medium will be investigated. The nutrient medium will be dosed with ENPs concentrations ranging from 1-1000 µg/L whereby the dissolved metal ions will be quantified using the ICP-OES with a detection limit of 1 µg/L. Dry powder ENPs will be characterised for size, size distribution, and morphology using TEM, surface area using BET, surface charge using Zetasizer, and surface crystallinity using XRD. In Hoagland’s media, the ENPs hydrodynamic size and surface charge as well as particle counts will be determined using Zetasizer and NTA, respectively. Secondly, the study will investigate the uptake dynamics of nAg and nZnO by an aquatic higher plant Spirodela punctuta, and evaluate their toxicity over a 20 day period. The role of hydrodynamic size, particle morphology as well as media ionic strength on ENP uptake and toxicity will be examined. Uptake investigations will be undertaken through SEM imaging inspection of plant sections whilst OxiSelect assay kits will be used to evaluate catalase activity, protein carbonyls, and free radical activity to ascertain potential ENPs linked induced toxicity. Through timeous analysis of chemical and physical state of ENPs, the proposed study envisages to generate detailed data useful to support sound hazard assessment and ultimately the risk assessment of metallic- and metal oxide-ENPs towards higher aquatic plants.enEngineered nanoparticlesENP'sInductively Coupled-Optical Emission SpectroscopyICO-OESTransmission electron microscopeTEMX-ray diffractionXRDBrunauer-Emmett-TellerBETNanotracking analysisNTAScanning electron microscopeSEMMetallic nanoparticlesNanoparticle characterisationParticle stabilityRisk assessmentConference PresentationRadebe, N., Thwala, M., Cele, L., Sikhwivhilu, L., Musee, N., & Shumbula, P. (2013). The stability of Ag and ZnO engineered nanoparticles in Hoagland's nutrient water: the role of particle size and morphology. http://hdl.handle.net/10204/7294Radebe, N, Melusi Thwala, LM Cele, L Sikhwivhilu, N Musee, and P Shumbula. "The stability of Ag and ZnO engineered nanoparticles in Hoagland's nutrient water: the role of particle size and morphology." (2013): http://hdl.handle.net/10204/7294Radebe N, Thwala M, Cele L, Sikhwivhilu L, Musee N, Shumbula P, The stability of Ag and ZnO engineered nanoparticles in Hoagland's nutrient water: the role of particle size and morphology; 2013. http://hdl.handle.net/10204/7294 .TY - Conference Presentation AU - Radebe, N AU - Thwala, Melusi AU - Cele, LM AU - Sikhwivhilu, L AU - Musee, N AU - Shumbula, P AB - The current study seeks to investigate the dissolution dynamics of silver (nAg) and zinc oxide (nZnO) engineered nanoparticles (ENPs), and how this affects their uptake by aquatic higher plants. First, the influence of particle size and morphology on the stability of nAg and nZnO in Hoagland’s nutrient medium will be investigated. The nutrient medium will be dosed with ENPs concentrations ranging from 1-1000 µg/L whereby the dissolved metal ions will be quantified using the ICP-OES with a detection limit of 1 µg/L. Dry powder ENPs will be characterised for size, size distribution, and morphology using TEM, surface area using BET, surface charge using Zetasizer, and surface crystallinity using XRD. In Hoagland’s media, the ENPs hydrodynamic size and surface charge as well as particle counts will be determined using Zetasizer and NTA, respectively. Secondly, the study will investigate the uptake dynamics of nAg and nZnO by an aquatic higher plant Spirodela punctuta, and evaluate their toxicity over a 20 day period. The role of hydrodynamic size, particle morphology as well as media ionic strength on ENP uptake and toxicity will be examined. Uptake investigations will be undertaken through SEM imaging inspection of plant sections whilst OxiSelect assay kits will be used to evaluate catalase activity, protein carbonyls, and free radical activity to ascertain potential ENPs linked induced toxicity. Through timeous analysis of chemical and physical state of ENPs, the proposed study envisages to generate detailed data useful to support sound hazard assessment and ultimately the risk assessment of metallic- and metal oxide-ENPs towards higher aquatic plants. DA - 2013-08 DB - ResearchSpace DP - CSIR KW - Engineered nanoparticles KW - ENP's KW - Inductively Coupled-Optical Emission Spectroscopy KW - ICO-OES KW - Transmission electron microscope KW - TEM KW - X-ray diffraction KW - XRD KW - Brunauer-Emmett-Teller KW - BET KW - Nanotracking analysis KW - NTA KW - Scanning electron microscope KW - SEM KW - Metallic nanoparticles KW - Nanoparticle characterisation KW - Particle stability KW - Risk assessment LK - https://researchspace.csir.co.za PY - 2013 T1 - The stability of Ag and ZnO engineered nanoparticles in Hoagland's nutrient water: the role of particle size and morphology TI - The stability of Ag and ZnO engineered nanoparticles in Hoagland's nutrient water: the role of particle size and morphology UR - http://hdl.handle.net/10204/7294 ER -