title: L-cysteine: a biocompatible, breathable and beneficial coating for graphene oxide.
abstract: Graphene oxide (GO) has been employed in various fields, and its ecological and health risks have attracted much attention. A small and inexpensive biomolecule, L-cysteine, was covalently immobilized onto GO to form L-cysteine-GO (CysGO) as a thio-functionalized nanosheet of 1.4 nm in thickness. Both the d-spacing and crystallinity of CysGO were observed to be lower than those of GO, whereas the D and G peaks remained similar to those of GO. CysGO exhibited remarkable uptake in vivo: no tissue defects, malformation, death or significant hatching delay were observed in zebrafish embryos. Significant DNA damage, decreased Na+/K+-ATPase activity and decreased mitochondrial membrane potential were not observed for CysGO. As a nonspecific activity linked to nanotoxicology, the unpaired electron spinning intensity of CysGO was approximately two orders of magnitude lower than that of GO. Oxygen microsensor analysis showed that the hypoxic and normoxic environments resulting from the presence of GO and CysGO envelopment, respectively, contributed to the difference in biocompatibility. CysGO also protected embryos from arsenic poisoning. Thus, CysGO has the advantageous properties of GO, exhibits excellent biocompatibility, acts as a breathable coating and antidote, and is suitable for various applications.
authors.affiliation: Institute of Agro-environmental Protection, Ministry of Agriculture, Tianjin 300191, China.
authors.forename: Li
authors.initials: L
authors.lastname: Mu
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. Electronic address: huxiangang@nankai.edu.cn.
authors.forename: Xiangang
authors.initials: X
authors.lastname: Hu
mesh_terms: D000818:Animals; D001151:Arsenic / Q000633:toxicity; D001672:Biocompatible Materials / Q000737:chemistry*; D002470:Cell Survival; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003460:Crystallization; D003470:Culture Media / Q000737:chemistry; D003545:Cysteine / Q000737:chemistry*; D004249:DNA Damage; D004578:Electron Spin Resonance Spectroscopy; D004625:Embryo, Nonmammalian; D005609:Free Radicals / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D053078:Membrane Potential, Mitochondrial; D018625:Microscopy, Atomic Force; D036103:Nanotechnology; D010087:Oxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000737:chemistry; D013499:Surface Properties; D015027:Zebrafish
chemical_list: D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D003470:Culture Media; D005609:Free Radicals; D010087:Oxides; D017382:Reactive Oxygen Species; D006108:Graphite; D003545:Cysteine; D001151:Arsenic; D010100:Oxygen
keywords: Biocompatibility; Detoxification; Free radical; Graphene oxide; Nanotoxicology; Surface modification