Effects of silver nanoparticles on wheat seedlings growth evaluated using ultra-weak photon emissions measurements / Efeitos das nanopartículas de prata no crescimento das plântulas de trigo avaliadas através de medições de emissões de fótons ultra fracos

Abstract

Ultra-weak photon emission (UWPE) is used to evaluate the effects of silver nanoparticles (AgNP) on wheat seeds germination. Three test series, using wheat seed samples in triplicate, irrigated by three different solutions: AgNP colloid, deionized water and sodium citrate dihydrate solution, had their UWPE data acquired for 24 hours at the fifth day of germination, inside an especially designed dark chamber. The photon-counts summation of each test was calculated, and correlated to its respective germination parameters – total biomass gain and total elongation of seedling aerial part. AgNP tests presented inferior total photon-counts summation and germination parameters levels, as compared to the tests using the other two solutions. Besides, the UWPE temporal profiles decreased over time for the AgNP tests, while for the other two test solutions the emission increased over time. Those results points changes in physiologic functions as deleterious effects of the AgNP contaminant. Principal Component Analysis (PCA) was applied, and the AgNP tests could be separated of the other tests due to germination parameters and UWPE data. The proposed method using UWPE measurements seems to be feasible to evaluate germination parameters of wheat seed in the presence of AgNP, and potentially in the presence of other contaminants.