Author(s): MEDEIROS, A. M. Z.; KHAN, L. U.; SILVA, G. H. da; OSPINA, C. A.; ALVES, O. L.; CASTRO, V. L. S. S. de; MARTINEZ, D. S. T.

Summary: Abstract: This work reports an integrated nanosafety study including the synthesis and characterization of the graphene oxide-silver nanoparticle hybrid material (GO-AgNPs) and its nano-ecotoxicity evaluation in the zebrafish embryo model. The influences of natural organic matter (NOM) and a chorion embryo membrane were considered in this study, looking towards more environmentally realistic scenarios and standardized nanotoxicity testing. The nanohybrid was successfully synthesized using the NaBH4 aqueous method, and AgNPs (~ 5.8 nm) were evenly distributed over the GO surface. GO-AgNPs showed a dose-response acute toxicity: the LC50 was 1.5 mg L-1 for chorionated embryos. The removal of chorion, however, increased this toxic effect by 50%. Furthermore, the presence of NOM mitigated mortality, and LC50 for GO-AgNPs changed respectively from 2.3 to 1.2 mg L-1 for chorionated and de-chorionated embryos. Raman spectroscopy confirmed the ingestion of GO by embryos; but without displaying acute toxicity up to 100 mg L-1, indicating that the silver drove toxicity down. Additionally, it was observed that silver nanoparticle dissolution has a minimal effect on these observed toxicity results. Finally, understanding the influence of chorion membranes and NOM is a critical step towards the standardization of testing for zebrafish embryo toxicity in safety assessments and regulatory issues.

Publication year: 2021

Types of publication: Journal article

Unit: Embrapa Environment

Keywords: Alternative methods, Composto de Carbono, Danio rerio, Ecotoxicology, Grafeno, Graphene oxide, Nanoecotoxicology, Nanohybrids, Nanomateriais, Nanomaterials, Nanotoxicity, Peixe de Água Doce, Toxidez, chorion