Year: 2016
Type: dissertation
Abstract: Engineered nanoparticles (ENPs) are increasingly being exploited in a whole range of applications and products due to their novel physicochemistry. Hence it is inevitable that ENPs will enter the environment at an increasing rate over the coming years. The consequential impact following interaction between ENPs with plants and soil microbial communities is of great concern given that they play fundamental roles in the environment and food production. \nIn this study, the impact of capped silver nanoparticles (cAg NPs) on terrestrial (Arabidopsis thaliana and Vicia faba) and aquatic (Lemna minor) plants was investigated. In addition, due to the important role of bacteria in plant survival and growth, this study also assessed the effect of cAg NPs on plant-associated soil microbial community structure. \ncAg NPs demonstrated varied toxicity towards plants and the associated soil microbes. Whilst the aquatic plants and soil microbial communities investigated in this study were not affected by cAg NPs up to 100 mg/L, for the terrestrial plants evaluated here, cAg NPs above 12 mg/L (specifically 50 and 100 mg/L) demonstrated differential toxic responses. Based on the results of this study, it is clear that concentration, exposure method, released ions, plant species, light intensity and growth mediums are key factors that influence the toxicity of cAg NPs. \nAlthough the cAg NP concentrations applied in this study are not yet environmentally relevant, with continued and uncontrolled commercial production of Ag NPs and/or in the event of spillage, such concentrations could occur in the environment in the future. \nChlorophyll fluorescence and gas exchange are valuable techniques for analysing the toxicity of ENPs on plants, due to their rapid and reliable results. Further studies in the interactions between plants and Ag NPs are urgently needed and would benefit from the use of different application methods such as aerosolization.
Author: Wael Obaid
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
SDG: Life on land
Open Access status: green
Funder: Taibah University
OpenAlex ID: W2563743014