Lyophilized and sonicated graphene oxide and its nanoecotoxicity applications

Abstract

The present work aimed to perform an exhaustive structural and chemical characterization of Lyophilized-Sonicated Graphene Oxide (L-SGO) and its nanoecotoxicological applications using Chlorella vulgaris and Lactuca sativa as biological models, exposed to 0.1, 1, 10 and 100 mg L−1 of L-SGO. In addition, both exposed and unexposed organisms to L-SGO were analyzed by optical and stereoscopic microscopy, scanning electronic microscopy (SEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and spectrofluorimetry. The 96 h-EC50 obtained for C. vulgaris was 37.52 mg L−1, and growth inhibition at the highest concentration tested (100 mg L−1) was 62.18 %. In L. sativa, germination (%) showed a significant difference between the control and the 100 mg L−1 treatment, while root elongation showed no differences between the treatments. Overall, this study demonstrated that L-SGO has slight or no toxicity on C. vulgaris and L. sativa at concentrations near and higher than 100 mg L−1, respectively, and showed that the toxicity of L-SGO is lower than that of other Graphene-related materials tested on these species. This study highlights the importance of graphene oxide like L-SGO to be used for multiple technological applications with which we can reducing pollution and having a relatively low impact on ecosystems.