Graphene oxide functionalized with ethylenediamine triacetic acid for heavy metal adsorption and anti-microbial applications

Abstract The development of functionalized nanomaterials that leads to multi-functionality, such as the ability to adsorb heavy metals coupled with anti-microbial properties is very attractive for diverse applications. The present study evaluated for the first time the antimicrobial activity of graphene oxide silanized with N-(trimethoxysilylpropyl) ethylenediamine triacetic acid (GO–EDTA) against Gram-negative, Cupriavidus metallidurans CH4, and Gram-positive bacteria, Bacillus subtilis , as well as its cytotoxicity to human corneal epithelial cell line hTCEpi. The results show that GO–EDTA has improved anti-microbial properties when compared to graphene oxide (GO) alone, with 92.3 ± 10% and 99.1 ± 1.3% cell inactivation of B. subtilis and C. metallidurans , respectively. Bacterial inactivation was attributed to an oxidative stress mechanism towards the cells. No cytotoxicity was observed towards human corneal epithelial cell lines hTCEp after 24 h exposure to GO–EDTA, suggesting that this nanomaterial has the potential for applications that have human exposure. This work also evaluated GO–EDTA’s adsorption capacity for two heavy metals, Cu 2+ and Pb 2+ at different concentrations, varying pH and contact time. The maximum adsorption capacity of the GO–EDTA was determined to be 454.6 mg g −1 and 108.7 mg g −1 for Pb 2+ and Cu 2+ , respectively, exceeding the capacity of traditional adsorbent materials, such as activated carbon.