abstract
Gold nanorods (AuNR) have been explored for many applications, including innovative nanomedicines, which also might contribute to its increase in the environment, namely due to inadequate disposable of wastes into aquatic environments. Early-life stages of amphibians are usually aquatic and sensitive to chemical contamination. Accordingly, this study aimed to determine the sublethal effects of CTAB functionalized AuNR on Xenopus laevis tadpoles. As such, tadpoles were exposed to serial concentrations of AuNR for 72 h. A reduction in the rate of feeding (EC50 = 4 mu g.L-1), snout to vent growth (EC50 = 5 mu g.L-1) and weight gain (EC50 = 6 mu g.L-1), was observed for AuNR-exposed tadpoles. Also, tadpoles actively avoided concentrations >= 4 mu g.L-1 of AuNR, after 12 h of exposure. At the biochemical level, AuNR caused impairments in antioxidant and nervous system related enzymes. Exposure to CTAB alone caused a high mortality. Results indicated that CTAB functionalized AuNR may induce several sublethal effects that may compromise the organism's fitness. Avoidance behavior (which corresponds to the disappearance of organisms, thus, similar to their death), observed at concentrations matching those inducing sublethal effects, suggest that it should be considered in the risk assessment for amphibians.
keywords
ACETYLCHOLINESTERASE ACTIVITY; INORGANIC NANOPARTICLES; TOXICITY; AVOIDANCE; TESTS; FATE
subject category
Engineering; Environmental Sciences & Ecology
authors
Costa, B; Quintaneiro, C; Daniel-da-Silva, AL; Trindade, T; Soares, AMVM; Lopes, I
our authors
Ana Luísa Daniel da Silva
Assistant Researcheracknowledgements
This study was also partially funded by Portuguese National Funds, FEDER funds within the PT2020 Partnership Agreement and Compete 2020-Programa Operacional Factores de Competitividade, and by the Portuguese Foundation for Science and Technology (FCT) through the strategic programme (UIDB/50017/2020 + UIDP/50017/2020) and the research projects (PTDC/BIA-BIC/3488/2012, POCI-01-0145-FEDER-030718, PTDC/AAG-MAA/2140/2012). Bruno Rafael Rabelo Costa received a Ph.D. grant from the Coordination for the Improvement of Higher Education Personnel (CAPES), 001268/2015-05 and support from the PhD program Biology and Ecology of Global Change from the Department of Biology, University of Aveiro, Portugal. The work of CQ is funded by national funds (OE), through FCT - Fundacao para a Ciencia e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19.