Graphene-based nanomaterials have received significant attention in the last decade due to their interesting properties. Its electrical and thermal conductivity and strength make graphene well suited for a variety of applications, particularly for use as a composite material in plastics. Furthermore, much work is taking place to utilize graphene as a biomaterial for uses such as drug delivery and tissue regeneration scaffolds. Owing to the rapid progress of graphene and its potential in many marketplaces, the potential toxicity of these materials has garnered attention. Graphene, while simple in its purest form, can have many different chemical and physical properties. In this paper, we describe our toxicity evaluation of pristine graphene and a functionalized graphene sample that has been oxidized for enhanced hydrophilicity, which was synthesized from the pristine sample. The samples were characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, infrared spectroscopy, thermogravimetric analysis, zeta-potential, atomic force microscopy and electron microscopy. We discuss the disagreement between the size of imaged samples analyzed by atomic force microscopy and by transmission electron microscopy. Furthermore, the samples each exhibit quite different surface chemistry and structure, which directly affects their interaction with aqueous environments and is important to consider when evaluating the toxicity of materials both in vitro and in vivo. Copyright © 2017 John Wiley & Sons, Ltd.
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http://dx.doi.org/10.1002/jat.3493 | DOI Listing |
J Colloid Interface Sci
December 2024
Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI), West Blvd. Azadi Sports Complex, P.O. Box 14665, 1998 Tehran, Iran.
Herein, a novel nanocomposite was developed to adjust the textural properties of metal-organic frameworks (MOFs) for adsorptive applications. To this end, nitrogen-doped carbon quantum dots/reduced graphene oxide nanocomposite (RC) was embedded into MIL-101(Cr) crystals, named RC-ML-x nanocomposites. The prepared nanoadsorbents were thoroughly characterized by different techniques.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78758, USA.
Theoretical calculations show that twisted double bilayer graphene (TDBG) under a transverse electric field develops a valley Chern number 2 at charge neutrality. Using thermodynamic and thermal activation measurements we report the experimental observation of a universal closing of the charge neutrality gap in the Hofstadter spectrum of TDBG at 1/2 magnetic flux per unit cell, in agreement with theoretical predictions for a valley Chern number 2 gap. Our theoretical analysis of the experimental data shows that the interaction energy, while larger than the flat-band bandwidth in TDBG near 1° does not alter the emergent valley symmetry or the single-particle band topology.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 210096, China.
As one of the core parts of the Internet-of-things (IOTs), multimodal sensors have exhibited great advantages in fields such as human-machine interaction, electronic skin, and environmental monitoring. However, current multimodal sensors substantially introduce a bloated equipment architecture and a complicated decoupling mechanism. In this work we propose a multimodal fusion sensing platform based on a power-dependent piecewise linear decoupling mechanism, allowing four parameters to be perceived and decoded from the passive wireless single component, which greatly broadens the configurable freedom of a sensor in the IOT.
View Article and Find Full Text PDFAnal Methods
January 2025
School of Public Health, Hebei Medical University, Shijiazhuang, 050017, P.R. China.
In this study, a molecularly imprinted electrochemical sensor (MIECS) was constructed based on the combination of graphene quantum dots-gold nanoparticles (GQDs-AuNPs), molecular imprinting polymer (MIP), and electrochemical technology for the ultra-sensitive detection of 17β-estradiol (E). GQDs-AuNPs were synthesized and modified on the surface of glassy carbon electrodes (GCE). Safranine T was used as the functional monomer and E was the template molecule for self-assembly and electropolymerization, thus generating an MIP film on the electrode surface.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Materials Science & International Institute of Intelligent Nanorobots and Nanosystems, State Key Laboratory of Surface Physics, Fudan University, Shanghai 200438, People's Republic of China.
Freestanding nanomembranes fabricated by lift-off technology have been widely utilized in microelectromechanical systems, soft electronics, and microrobotics. However, a conventional chemical etching strategy to eliminate nanomembrane adhesion often restricts material choice and compromises quality. Herein, we propose a nanomembrane-on-graphene strategy that leverages the weak van der Waals adhesion on graphene to achieve scalable and controllable release and 3D construction of nanomembranes.
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