As the rapid development of nanotechnology, the application of nanomaterials in environmental chemistry has become an important frontier in modern environmental engineering. Particularly, graphene oxide (GO) and GO-based nanomaterials have attracted widespread attentions in the field of chem-/bio-chemical analysis by virtue of their unique structure, optical and electrical properties. However, with the two-dimensional (2D) planar structure, 2D graphene-based nanomaterials are still suffering from agglomeration, which would shield their abundant active sites, resulting in a significant drop of their catalytic activity and stability. To meet the urgent requirements of environmental monitoring and remediation, we have designed a series of chem-/bio-sensors based on three-dimensional (3D) graphene-based materials and further explored new methods for pollutants detection. We have successfully fabricated a 3D graphene/Fe3O4-AuNPs with flexibly switchable peroxidase-like activity. Compared to the traditional 2D graphene-based composites, the introduced 3D structure dramatically improved the catalytic activity, as well as the catalysis velocity and its affinity for substrate. Notably, the catalytic activity was able to be regulated by the adsorption and desorption of DNA. Accordingly, based on the peroxidase-like activity and its controllability, our prepared 3D hybrids was successfully adopted in the visualized and label-free detections for glucose, sequence-specific DNA, mismatched nucleotides, and oxytetracycline (OTC). Besides assembling into 3D porous graphene hybrids, GO can also be readily assembled into 3D macrostructures. Integrating with adenosine and aptamer worked as co-crosslinkers, we prepared a GO-based hydrogel and realized the fluorescent detection for OTC. The as-prepared hydrogel showed high mechanical strength and thermal stability. The optimal hydrogel exhibited comparable response for OTC. Moreover, together with the high affinity of the aptamer for its target, this assay exhibited excellent sensitivity and selectivity, as well as universality. The developed strategy was also tested to possess the feasibility of in situ OTC detection in real samples. We suppose that these strategies will inspire the development and application of 3D graphene-based structures for environmental applications, such as water purification, gas adsorption and optical or electrochemical sensors design.

Three-dimensional graphene-based nanomaterials for pollutants detection

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.