Widely distributed nanocolloids in water regulate the fate and risk of graphene oxide
Graphical abstract
Introduction
Natural colloids with a size range from approximately 1 to 1000 nm are important environmental components and widely present in aqueous environments (Stolpe et al., 2013; Zhou et al., 2016). Compared to large-scale colloids (100–1000 nm), nanocolloids (Nc, approximately 1–100 nm) have a large specific surface area and high dispersity, which may play an important role in the fate and bioavailability of pollutants in the aquatic environment (Santschi, 2018; Xu et al., 2018), although the related information remains obscure. Graphene oxide (GO), a two-dimensional carbon-based nanomaterial, presents unique structural and physical properties that highlight its applicability in various areas, such as energy storage (Georgakilas et al., 2016), biomedicine (Lee et al., 2016) and environmental protection (Joshi et al., 2014). Since GO released to aquatic systems will most likely interact with Nc, a deep understanding of the basic interactions between GO and Nc may help to better clarify the potential risks of GO and provide guidance on the safe design of GO.
Given the complex compositions of Nc, analyzing the interaction analysis between nanomaterials and Nc remains challenging. Two-dimensional correlation spectroscopy (2DCOS) that is capable of resolving overlapped peaks could probe the interaction mechanisms of complex compounds (Phong and Hur, 2018; Yan et al., 2013). Herein, a 2DCOS analysis that integrates synchronous fluorescence and Fourier transform infrared spectroscope (FTIR) was performed to provide an in-depth understanding of the binding characteristic mechanisms of Nc onto GO at the molecular level. The affinity interactions between Nc and GO are fundamental to understanding the effects of Nc on the environmental behaviors of GO. Biolayer interferometry (BLI) is a real-time and label-free optical technique that using fiber-optic biosensors to accurately quantify and measure the affinity between molecules, such as protein−protein, protein−nucleic acids, and protein−small molecules (Gao et al., 2017; Hjuler et al., 2017). In recent years, BLI has successfully used to investigate the interactions between GO and molecules, such as proteins, single-stranded DNA (ssDNA) and humic acid (HA) (Zhou et al., 2019). Herein, BLI was used to directly and accurately detect the binding affinity between GO and Nc.
The colloidal behaviors of GO with dissolved organic matter (DOM) or environmentally relevant cations (e.g., Ca2+ and Na+) have been extensively studied (Chowdhury et al., 2015; Yang et al., 2016). For example, Chowdhury et al. observed that DOM improved GO dispersion and divalent cations enhanced GO aggregation (Chowdhury et al., 2013). The roles of three common geogenic minerals (montmorillonite, kaolinite, and goethite) with different surface charge properties and geometric dimensions in the GO−mineral heteroaggregation and the environmental fate of GO were also investigated (Zhao et al., 2015). In contrast, Nc were extracted from the natural environment and contained inorganic mineral colloids (e.g., Fe and Mn oxides and aluminosilicates), aromatic refractory organic matter binding heavy metals, and rigid biopolymers (Buffle et al., 1998; Ouyang et al., 2018). However, effects of Nc on the aggregation, adsorption and morphological transformation of engineered nanoparticles (ENPs) remain largely unknown. GO with shape edges exhibited high colloidal stability, which led to adverse effects and sufficient direct contact on Escherichia coli, Chlorella pyrenoidosa or zebrafish (Akhavan and Ghaderi, 2010; Souza et al., 2017; Zhao et al., 2018). Compared to studies on the adverse effects of pristine GO, investigations into the environmental risks of the GO binding with Nc are much more meaningful. In the present work, the main objectives were to explore the effects of Nc on the morphology, aggregation, uptake and ecotoxicity of GO after binding. Zebrafish as a model was used as the tested organism. The findings will provide new insights into the fate and risks of ENPs under the influence of Nc at environmental concentrations.
Section snippets
Sampling, isolation and enrichment of Nc
The Haihe River with the mainstream length 105 km, an average width of approximately 100 m, and an average depth of 6.5 m, is the one of the seven largest basins in China (Liu et al., 2007). Because the river receives domestic, industrial, and agricultural pollutants from Tianjin City, Hebei Province and Beijing City, the Haihe River has been profoundly contaminated (Niu et al., 2018). According to our recent work, the concentrations of Nc ranged from 3.7 to 7.2 mg/L with similar morphologies,
Complicated Nc enriched from surface water
The morphology and size distribution of the Nc were examined via transmission electron microscopy (TEM) and atomic force microscopy (AFM) (Fig. S2a−2d). Most of the observed Nc presented irregular or flaky grain shapes, and the size and the thickness of the Nc were predominantly (>70%) smaller than 40 nm and 10 nm, respectively. The Nc with size ranges of 1–20 and 21–40 nm accounted for 42% and 50%, respectively (Fig. S2b). The mean size of the Nc was approximately 20 nm. Furthermore, the AFM
Conclusions
In the present study, the multiple analytical methods (e.g., BLI and 2DCOS) revealed that the Nc exhibited a high binding affinity onto GO via hydrophilic effects, electron charge transfers and π-π stacking interactions. Nc adsorption also promoted the dispersity of GO in water. After binding to Nc, the properties (e.g. morphology and structure) of GO changed. Morphology was a critical factor that affected graphene nanotoxicity (Hu et al., 2015). The pristine GO was transformed into a scroll
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
This work was financially supported by the National Natural Science Foundation of China (grant nos. 21722703, 21677080 and 31770550).
References (57)
- et al.
Heteroaggregation and sedimentation of graphene oxide with hematite colloids: influence of water constituents and impact on tetracycline adsorption
Sci. Total Environ.
(2019) - et al.
Enzyme-linked, aptamer-based, competitive biolayer interferometry biosensor for palytoxin
Biosens. Bioelectron.
(2017) - et al.
Investigation of adsorptive fractionation of humic acid on graphene oxide using fluorescence EEM-PARAFAC
Water Res.
(2015) - et al.
Biosensors based on graphene oxide and its biomedical application
Adv. Drug Deliv. Rev.
(2016) - et al.
Occurrence of polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls pollution in sediments from the Haihe River and Dagu Drainage river in Tianjin City, China
Chemosphere
(2007) - et al.
Ecological risk assessment of microcystin-LR in the upstream section of the Haihe River based on a species sensitivity distribution model
Chemosphere
(2018) - et al.
The reduction of graphene oxide
Carbon
(2012) - et al.
Preparation and characterization of graphene oxide nanosheets
Procedia Eng.
(2012) Marine colloids, agents of the self-cleansing capacity of aquatic systems: historical perspective and new discoveries
Mar. Chem.
(2018)- et al.
Towards more ecological relevance in sediment toxicity testing with fish: evaluation of multiple bioassays with embryos of the benthic weatherfish (Misgurnus fossilis)
Sci. Total Environ.
(2018)
Toxicological effects of graphene oxide on adult zebrafish (Danio rerio)
Aquat. Toxicol.
Abundance, size distributions and trace-element binding of organic and iron-rich nanocolloids in Alaskan rivers, as revealed by field-flow fractionation and ICP-MS
Geochem. Cosmochim. Acta
Characterization, origin and aggregation behavior of colloids in eutrophic shallow lake
Water Res.
Study of iron and aluminum binding to Suwannee River fulvic acid using absorbance and fluorescence spectroscopy: comparison of data interpretation based on NICA-Donnan and Stockholm humic models
Water Res.
Effects of humic acid on copper adsorption onto few-layer reduced graphene oxide and few-layer graphene oxide
Carbon
Flocculation performance and mechanism of graphene oxide for removal of various contaminants from water
Water Res.
Colloidal size spectra, composition and estuarine mixing behavior of DOM in river and estuarine waters of the northern Gulf of Mexico
Geochem. Cosmochim. Acta
Toxicity of graphene and graphene oxide nanowalls against bacteria
ACS Nano
Lipid–lipid interactions in aminated reduced graphene oxide interface for biosensing application
Langmuir
Structural basis of potent zika–dengue virus antibody cross-neutralization
Nature
Nanoparticles induce dermal and intestinal innate immune system responses in zebrafish embryos
Environ. Sci.: Nano
A generalized description of aquatic colloidal interactions: the three-colloidal component approach
Environ. Sci. Technol.
Nanoecotoxicity assessment of graphene oxide and its relationship with humic acid
Environ. Toxicol. Chem.
Mitigation in multiple effects of graphene oxide toxicity in zebrafish embryogenesis driven by humic acid
Environ. Sci. Technol.
Reduced cytotoxicity of graphene nanosheets mediated by blood-protein coating
ACS Nano
Colloidal properties and stability of graphene oxide nanomaterials in the aquatic environment
Environ. Sci. Technol.
Aggregation and stability of reduced graphene oxide: complex roles of divalent cations, pH, and natural organic matter
Environ. Sci. Technol.
Electrophysiological characterization of membrane disruption by nanoparticles
ACS Nano
Cited by (22)
Graphene oxide affects bacteriophage infection of bacteria by promoting the formation of biofilms
2023, Science of the Total EnvironmentEffect of natural soil nanocolloids on the fate and toxicity of cadmium to rice (Oryza sativa L.) roots
2023, Science of the Total Environment