다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Graphene has attracted tremendous research interest in recent years, owing to its exceptional properties. The scaled-up and reliable production of graphene derivatives, such as graphene oxide (GO) and reduced graphene oxide (rGO), offers a wide range of possibilities to synthesize graphene-based functional materials for various applications. This critical review presents and discusses the current development of graphene-based composites. After introduction of the synthesis methods for graphene and its derivatives as well as their properties, we focus on the description of various methods to synthesize graphene-based composites, especially those with functional polymers and inorganic nanostructures. Particular emphasis is placed on strategies for the optimization of composite properties. Lastly, the advantages of graphene-based composites in applications such as the Li-ion batteries, supercapacitors, fuel cells, photovoltaic devices, photocatalysis, as well as Raman enhancement are described (279 references).

/pdf/graphene-based-composites-540z2xd3o0.pdf

Graphene-based composites

Graphene based materials: Past, present and future

Lanthanide-based luminescent hybrid materials.

Graphene oxide: preparation, functionalization, and electrochemical applications.

Novel nanomaterials, such as nanowires and carbon nanotubes (CNTs), have attracted considerable attention in electrical detection of chemical and biological species for clinical diagnosis and practical pharmaceutical applications during the past decade. [ 1–3 ] Electrical detection of biomolecules using nanomaterials can often achieve high sensitivity because nanomaterials are extremely sensitive to electronic perturbations in the surrounding environment. By using CNTs and CNT-based fi eldeffect transistors (FETs), biosensors have been demonstrated for the detection of protein binding [ 4–7 ] and DNA hybridization events. [ 8 , 9 ] The detection limit of reported CNT protein sensors is normally at 0.1–10 nM level, [ 2 , 5 , 10 ] and an improved detection limit could reach 1 ng/ml through cleaving the protein using an enzyme. [ 7 ] Although CNT devices are promising candidates for biosensors with high sensitivity, the variation in the device characteristics is an obstacle to the device reliability and the device sensitivity is still limited by surface area and electrical properties of CNTs. Graphene, a single layer of carbon atoms in a two-dimensional honeycomb lattice, has potential applications in the electrical detection of biological species due to their unique physical properties. [ 11–13 ] Intrinsic graphene is a zero-gap semiconductor that has remarkably high electron mobility ( ∼ 15 000 cm 2 ⋅ V − 1 ⋅ s − 1 ) at room temperature, [ 12 ] which is even higher than that of CNTs. [ 14 ] Although graphene has been explored for various applications, [ 15–26 ] there are only limited reports on graphenebased biosensors until recently. [ 27–33 ] For instance, large-sized graphene fi lm FETs were fabricated for the electrical detection of DNA hybridization; [ 27 ] graphene oxide (GO) was used in single-bacterium and label-free DNA sensors. [ 29 ] In addition, electrolyte-gated graphene FETs for electrical detection of pH and protein adsorption were reported. [ 30 ] Despite the sparse demonstration of graphene for biosensing applications, graphene-based FETs have not been reported for detection of protein binding (antibody to antigen) events. Because the carrier

Specific Protein Detection Using Thermally Reduced Graphene Oxide Sheet Decorated with Gold Nanoparticle‐Antibody Conjugates

Graphene is worth evaluating for chemical sensing and biosensing due to its outstanding physical and chemical properties. We first report on the fabrication and characterization of gas sensors using a back-gated field-effect transistor platform with chemically reduced graphene oxide (R-GO) as the conducting channel. These sensors exhibited a 360% increase in response when exposed to 100 ppm NO2 in air, compared with thermally reduced graphene oxide sensors we reported earlier. We then present a new method of signal processing/data interpretation that addresses (i) sensing devices with long recovery periods (such as required for sensing gases with these R-GO sensors) as well as (ii) device-to-device variations. A theoretical analysis is used to illuminate the importance of using the new signal processing method when the sensing device suffers from slow recovery and non-negligible contact resistance. We suggest that the work reported here (including the sensor signal processing method and the inherent simpl...

Toward Practical Gas Sensing with Highly Reduced Graphene Oxide: A New Signal Processing Method To Circumvent Run-to-Run and Device-to-Device Variations

Vertically oriented graphene (VG) nanosheets have attracted growing interest for a wide range of applications, from energy storage, catalysis and field emission to gas sensing, due to their unique orientation, exposed sharp edges, non-stacking morphology, and huge surface-to-volume ratio. Plasma-enhanced chemical vapor deposition (PECVD) has emerged as a key method for VG synthesis; however, controllable growth of VG with desirable characteristics for specific applications remains a challenge. This paper attempts to summarize the state-of-the-art research on PECVD growth of VG nanosheets to provide guidelines on the design of plasma sources and operation parameters, and to offer a perspective on outstanding challenges that need to be overcome to enable commercial applications of VG. The review starts with an overview of various types of existing PECVD processes for VG growth, and then moves on to research on the influences of feedstock gas, temperature, and pressure on VG growth, substrate pretreatment, the growth of VG patterns on planar substrates, and VG growth on cylindrical and carbon nanotube (CNT) substrates. The review ends with a discussion on challenges and future directions for PECVD growth of VG.

/pdf/plasma-enhanced-chemical-vapor-deposition-synthesis-of-1ezh0ofcz5.pdf

Plasma-enhanced chemical vapor deposition synthesis of vertically oriented graphene nanosheets

The current global energy problem can be attributed to insufficient fossil fuel supplies and excessive greenhouse gas emissions resulting from increasing fossil fuel consumption. The huge demand for clean energy potentially can be met by solar-to-electricity conversions. The large-scale use of solar energy is not occurring due to the high cost and inadequate efficiencies of existing solar cells. Nanostructured materials have offered new opportunities to design more efficient solar cells, particularly one-dimensional (1-D) nanomaterials for enhancing solar cell efficiencies. These 1-D nanostructures, including nanotubes, nanowires, and nanorods, offer significant opportunities to improve efficiencies of solar cells by facilitating photon absorption, electron transport, and electron collection; however, tremendous challenges must be conquered before the large-scale commercialization of such cells. This review specifically focuses on the use of 1-D nanostructures for enhancing solar cell efficiencies. Other nanostructured solar cells or solar cells based on bulk materials are not covered in this review. Major topics addressed include dye-sensitized solar cells, quantum-dot-sensitized solar cells, and p-n junction solar cells.

/pdf/enhancing-solar-cell-efficiencies-through-1-d-nanostructures-4fu8ylrpgr.pdf

Enhancing Solar Cell Efficiencies through 1-D Nanostructures

We report a novel and selective gas-sensing platform with reduced graphene oxide (RGO) decorated with tin oxide (SnO2) nanocrystals (NCs). This hybrid SnO2 NC–RGO platform showed enhanced NO2 but weakened NH3 sensing compared with bare RGO, showing promise in tuning the sensitivity and selectivity of RGO-based gas sensors.

/pdf/tuning-gas-sensing-properties-of-reduced-graphene-oxide-4bb9rii2ef.pdf

Kehan Yu

Papers

Specific Protein Detection Using Thermally Reduced Graphene Oxide Sheet Decorated with Gold Nanoparticle‐Antibody Conjugates

Toward Practical Gas Sensing with Highly Reduced Graphene Oxide: A New Signal Processing Method To Circumvent Run-to-Run and Device-to-Device Variations

Plasma-enhanced chemical vapor deposition synthesis of vertically oriented graphene nanosheets

Enhancing Solar Cell Efficiencies through 1-D Nanostructures

Tuning gas-sensing properties of reduced graphene oxide using tin oxide nanocrystals