Fluorescence Emission Spectrum of Elodea Leaves Exposed to Nanoparticles

The intensive use of engineered nanoparticles (NPs) in industrial, agricultural and household applications will very likely lead to the release of such materials into the environment, especially water ecosystems. Water plants are an integral part of ecosystems; hence their interaction with NPs is inevitable. It is important to understand the consequences of this interaction and assess its potential effects. There are different types of approaches for investigating the toxic effects of NPs on plants. Chlorophyll fluorescence (ChlF) is one of interesting biophysical methods for testing the effects NPs on plants in vivo. ChlF is a suitable technique and a very powerful tool for the in vivo studying of photochemical and non-photochemical processes within thylakoid membranes, chloroplasts, plant tissues, and whole plants. The present work reports the in vivo observation of chlorophyll a fluorescence quenching induced by the iron (Fe₃O₄, Fe₂O₃) and aluminum oxide (Al₂O₃) nanoparticles. Excitation and emission spectra of intact leaves of Elodea were acquired by fluorescence spectrophotometer (Cary Eclipse) at room temperature. It was shown that the intensity of the ChlF decreased in the solution of Fe₃O₄ and Al₂O₃ nanoparticles on the light. Fe₂O₃ affected slightly and the toxicity of nanoparticles depended on dose and exposure period. It was clear from these experiments that the given nanoparticles penetrated into the cell and might decrease the chlorophyll content of leaves.