Raman spectrum of graphene and graphene layers.
TL;DR: This work shows that graphene's electronic structure is captured in its Raman spectrum that clearly evolves with the number of layers, and allows unambiguous, high-throughput, nondestructive identification of graphene layers, which is critically lacking in this emerging research area.
Abstract: Graphene is the two-dimensional building block for carbon allotropes of every other dimensionality We show that its electronic structure is captured in its Raman spectrum that clearly evolves with the number of layers The D peak second order changes in shape, width, and position for an increasing number of layers, reflecting the change in the electron bands via a double resonant Raman process The G peak slightly down-shifts This allows unambiguous, high-throughput, nondestructive identification of graphene layers, which is critically lacking in this emerging research area
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TL;DR: In this article, a straightforward strategy is designed for the fabrication of CuFe2O4-graphene heteroarchitecture via a one-step hydrothermal route to allow multifunctional properties, i.e., magnetic cycling, high photocatalytic activity under visible light irradiation, and excellent electrochemical behaviors for use as the anode in lithium-ion batteries (LIBs).
Abstract: A straightforward strategy is designed for the fabrication of CuFe2O4-graphene heteroarchitecture via a one-step hydrothermal route to allow multifunctional properties, i.e., magnetic cycling, high photocatalytic activity under visible light irradiation, and excellent electrochemical behaviors for use as the anode in lithium-ion batteries (LIBs). Transmission electron microscopy (TEM) observations indicate that graphene sheets are exfoliated and decorated with hexagonal CuFe2O4 nanoflakes. The photocatalytic activity measurements demonstrate that the combination of CuFe2O4 and graphene results in a dramatic conversion of the inert CuFe2O4 into a highly active catalyst for the degradation of methylene blue (MB) under visible light irradiation. CuFe2O4 nanoparticles themselves have excellent magnetic properties, which makes the CuFe2O4-graphene heteroarchitecture magnetically recyclable in a suspension system. It should be pointed out that the CuFe2O4-graphene (with 25 wt % graphene) heteroarchitecture as a...
187 citations
TL;DR: It is critical to synthesize high-quality graphene on a large scale to envision graphene technology, and intense efforts have been made to develop methods for graphene synthesis, including reduction of graphene oxide, thermal decomposition of SiC, and others.
Abstract: Graphene, a single atomic layer of hexagonally packed carbon atoms, has drawn signifi cant attention with its outstanding electrical, [ 1 ] mechanical, [ 2 , 3 ] and chemical properties. [ 4 , 5 ] Various promising applications based on graphene have been demonstrated, such as in electronics, [ 6 , 7 ] optoelectronics, [ 8 , 9 ] and chemical and biological sensing. [ 10–12 ] To further envision graphene technology, it is critical to synthesize high-quality graphene on a large scale. Since the fi rst mechanical isolation of graphene from graphite crystal in 2004, [ 13 ] intense efforts have been made to develop methods for graphene synthesis, including reduction of graphene oxide, [ 14 ] thermal decomposition of SiC, [ 15 , 16 ]
187 citations
TL;DR: In this article, a few-layer nitrogen-doped graphene (FLNG) was successfully prepared by a simple bottom-up synthesis of technique using Dicyandiamide and Coal tar pitch as raw materials.
186 citations
TL;DR: The current work presents an important concept toward the application of nanomaterial-based FET sensors for biochemical sensing in physiological environments and thus could lead to powerful tools for basic research and healthcare.
Abstract: Nanomaterial-based field-effect transistor (FET) sensors are capable of label-free real-time chemical and biological detection with high sensitivity and spatial resolution, although direct measurements in high–ionic-strength physiological solutions remain challenging due to the Debye screening effect. Recently, we demonstrated a general strategy to overcome this challenge by incorporating a biomolecule-permeable polymer layer on the surface of silicon nanowire FET sensors. The permeable polymer layer can increase the effective screening length immediately adjacent to the device surface and thereby enable real-time detection of biomolecules in high–ionic-strength solutions. Here, we describe studies demonstrating both the generality of this concept and application to specific protein detection using graphene FET sensors. Concentration-dependent measurements made with polyethylene glycol (PEG)-modified graphene devices exhibited real-time reversible detection of prostate specific antigen (PSA) from 1 to 1,000 nM in 100 mM phosphate buffer. In addition, comodification of graphene devices with PEG and DNA aptamers yielded specific irreversible binding and detection of PSA in pH 7.4 1x PBS solutions, whereas control experiments with proteins that do not bind to the aptamer showed smaller reversible signals. In addition, the active aptamer receptor of the modified graphene devices could be regenerated to yield multiuse selective PSA sensing under physiological conditions. The current work presents an important concept toward the application of nanomaterial-based FET sensors for biochemical sensing in physiological environments and thus could lead to powerful tools for basic research and healthcare.
186 citations
Cites background or methods from "Raman spectrum of graphene and grap..."
...S2) are consistent with monolayer graphene (30, 31)....
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...Raman spectroscopy is widely used to characterize the quality and doping level of graphene films (30)....
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...5, which is consistent with monolayer graphene (30)....
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TL;DR: In this article, the influence of transfer parameters on the final structure, morphology and electrical properties of graphene were investigated, and it was shown that a double layer of PMMA can enhance or degrade graphene quality depending on its concentration.
186 citations
Cites background from "Raman spectrum of graphene and grap..."
...[23] Ferrari AC, Meyer JC, Scardaci V, et al....
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References
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28 Jul 2005
TL;DR: PfPMP1）与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。
18,940 citations