Graphene-Based Materials for Biosensors: A Review <s> Graphene-Based Materials: Fabrication Process and Properties <s> The surface area of a single graphene sheet is 2630 m2/g, substantially higher than values derived from BET surface area measurements of activated carbons used in current electrochemical double layer capacitors. Our group has pioneered a new carbon material that we call chemically modified graphene (CMG). CMG materials are made from 1-atom thick sheets of carbon, functionalized as needed, and here we demonstrate in an ultracapacitor cell their performance. Specific capacitances of 135 and 99 F/g in aqueous and organic electrolytes, respectively, have been measured. In addition, high electrical conductivity gives these materials consistently good performance over a wide range of voltage scan rates. These encouraging results illustrate the exciting potential for high performance, electrical energy storage devices based on this new class of carbon material. <s> BIB001 </s> Graphene-Based Materials for Biosensors: A Review <s> Graphene-Based Materials: Fabrication Process and Properties <s> We present a low-temperature (300–400 °C), large-area (23 cm×20 cm) and efficient synthesis method for graphene-based transparent conductive films using surface wave plasma chemical vapor deposition. The films consist of few-layer graphene sheets. Their transparency and conductivity characteristics make them suitable for practical electrical and optoelectronic applications, which have been demonstrated by the proper operation of a touch panel fabricated using the films. The results confirm that our method could be suitable for the industrial mass production of macroscopic-scale graphene-based films. <s> BIB002 </s> Graphene-Based Materials for Biosensors: A Review <s> Graphene-Based Materials: Fabrication Process and Properties <s> This review is based on the Theophilus Redwood Medal and Award lectures, delivered to Royal Society of Chemistry meetings in the UK and Ireland in 2012, and presents a personal overview of the field of biosensors. The biosensors industry is now worth billions of United States dollars, the topic attracts the attention of national initiatives across the world and tens of thousands of papers have been published in the area. This plethora of information is condensed into a concise account of the key achievements to date. The reasons for success are examined, some of the more exciting emerging technologies are highlighted and the author speculates on the importance of biosensors as a ubiquitous technology of the future for health and the maintenance of wellbeing. <s> BIB003 </s> Graphene-Based Materials for Biosensors: A Review <s> Graphene-Based Materials: Fabrication Process and Properties <s> Abstract Interest in two-dimensional, sheet-like or flake-like carbon forms has expanded beyond monolayer graphene to include related materials with significant variations in layer number, lateral dimension, rotational faulting, and chemical modification. Describing this family of “graphene materials” has been causing confusion in the Carbon journal and in the scientific literature as a whole. The international editorial team for Carbon believes that the time has come for a discussion on a rational naming system for two-dimensional carbon forms. We propose here a first nomenclature for two-dimensional carbons that could guide authors toward a more precise description of their subject materials, and could allow the field to move forward with a higher degree of common understanding. <s> BIB004 </s> Graphene-Based Materials for Biosensors: A Review <s> Graphene-Based Materials: Fabrication Process and Properties <s> Graphene materials have entered a phase of maturity in their development that is characterized by their explorative utilization in various types of applications and fields from electronics to biomedicine. Herein, we describe the recent advances made with graphene-related materials in the biomedical field and the challenges facing these exciting new tools both in terms of biological activity and toxicological profiling in vitro and in vivo. Graphene materials today have mainly been explored as components of biosensors and for construction of matrices in tissue engineering. Their antimicrobial activity and their capacity to act as drug delivery platforms have also been reported, however, not as coherently. This report will attempt to offer some perspective as to which areas of biomedical applications can expect graphene-related materials to constitute a tool offering improved functionality and previously unavailable options. <s> BIB005 </s> Graphene-Based Materials for Biosensors: A Review <s> Graphene-Based Materials: Fabrication Process and Properties <s> The chemical reduction of graphene oxide is a promising route towards the large scale production of graphene for commercial applications. The current state-of-the-art in graphene oxide reduction, consisting of more than 50 types of reducing agent, will be reviewed from a synthetic chemistry point of view. Emphasis is placed on the techniques, reaction mechanisms and the quality of the produced graphene. The reducing agents are reviewed under two major categories: (i) those which function according to well-supported mechanisms and (ii) those which function according to proposed mechanisms based on knowledge of organic chemistry. This review will serve as a valuable platform to understand the efficiency of these reducing agents for the reduction of graphene oxide. <s> BIB006 </s> Graphene-Based Materials for Biosensors: A Review <s> Graphene-Based Materials: Fabrication Process and Properties <s> In this review, we analyze several types of graphene-based sensors for glucose detection with respect to their preparation, properties and efficiency in electro-chemical processes. Graphene may display different types of defects, which play a role in the electron transfer processes. Oxygenated groups on the edges of graphene planes reduce the graphene in-plane conductivity, but may enhance the heterogeneous electron/proton transfer constant. Other positive effects of defects are related to the shortening of the distance between active centers and electrodes upon enzyme or protein immobilization. However, though by different mechanisms, all types of graphene enhance the electrochemical response at the electrode. <s> BIB007 </s> Graphene-Based Materials for Biosensors: A Review <s> Graphene-Based Materials: Fabrication Process and Properties <s> Graphene-based materials have attracted increasing attention due to their atomically-thick two-dimensional structures, high conductivity, excellent mechanical properties, and large specific surface areas. The combination of biomolecules with graphene-based materials offers a promising method to fabricate novel graphene–biomolecule hybrid nanomaterials with unique functions in biology, medicine, nanotechnology, and materials science. In this review, we focus on a summarization of the recent studies in functionalizing graphene-based materials using different biomolecules, such as DNA, peptides, proteins, enzymes, carbohydrates, and viruses. The different interactions between graphene and biomolecules at the molecular level are demonstrated and discussed in detail. In addition, the potential applications of the created graphene–biomolecule nanohybrids in drug delivery, cancer treatment, tissue engineering, biosensors, bioimaging, energy materials, and other nanotechnological applications are presented. This review will be helpful to know the modification of graphene with biomolecules, understand the interactions between graphene and biomolecules at the molecular level, and design functional graphene-based nanomaterials with unique properties for various applications. <s> BIB008 </s> Graphene-Based Materials for Biosensors: A Review <s> Graphene-Based Materials: Fabrication Process and Properties <s> Abstract Graphene has contributed to the fabrication of sensitive sensors and biosensors due to its physical and electrochemical properties. This review discusses the role of graphene and graphene related materials for the improvement of the analytical performance of sensors and biosensors. This paper also provides an overview of recent graphene based sensors and biosensors (2012–2016), comparing their analytical performance for application in clinical, environmental, and food sciences research, and comments on future and interesting research trends in this field. <s> BIB009
The synthesis of graphene-based materials in a presence of different methods can be controlled to confer properties for specific and desirable applications. Figure 2 shows the major types of graphene-based materials having been useful for engineering biosensors. The structure of pristine graphene is characterized as the array of 2D and sp BIB003 -hybridization of pure carbon atoms arranged in a hexagonal lattice with covalent bonds. Meanwhile, functionalized graphenes are achieved by synthesis and preparation, for examples, the carbon core structure can be oxidized forming GO, the The emergence of graphene, a two-dimensional (2D) nanomaterial, has played a tremendous role in the electronic and sensor communities. Graphene is defined as "a single-atom-thick sheet of hexagonally arranged, sp 2 -bonded carbon atoms occurring within a carbon material structure" BIB004 . The nano-thickness graphene film with 100 µm of lateral size is observed as carbon planes connected together by van der Waals forces acting over a distance of about 0.335 nm. The properties of graphene are those of a semi-metal and are stable under ambient circumstances. This contradicts the general belief that a 2D material could not exist and be thermodynamically stable. The charge transport and electronic properties of graphene are due to its unique electronic band structure. In particular, among existing nanomaterials graphene has a large surface area (2630 m 2 /g) BIB001 BIB002 being available for direct interaction in a wide range of biomolecules BIB008 . Graphene can be engineered with structural defects using low-cost fabrication methods due to the migration of heteroatoms, oxidation, and reduction by chemical modification  BIB006 . The uses of graphene-based materials for biosensing involve two points of view. One is based on charge-biomolecule interactions at π-π domains, electrostatic forces and charge exchange leading to electrical variations in the pristine graphene. The other uses are the effect of defects, disorder, the chemical functionalization to immobilize the molecular receptors onto the surface of graphene oxide (GO), reduced graphene oxide (RGO) and graphene-based quantum dots (GQDs). Recently, several excellent reviews have focused on the interactions of graphene, GO and RGO-based biosensors with their biomolecular targets BIB008 BIB009 BIB007 BIB005 . In this review, we focus on the graphene-based material properties due to their fabrication process, surface chemistry and the photoluminescent graphene so-called GQDs. These graphene properties are utilized and integrated in biosensors for biological and medical applications. The synthesis of graphene-based materials in a presence of different methods can be controlled to confer properties for specific and desirable applications. Figure 2 shows the major types of graphene-based materials having been useful for engineering biosensors. The structure of pristine graphene is characterized as the array of 2D and sp 2 -hybridization of pure carbon atoms arranged in a hexagonal lattice with covalent bonds. Meanwhile, functionalized graphenes are achieved by synthesis and preparation, for examples, the carbon core structure can be oxidized forming GO, the reduced structure with vacancy defects is RGO, structures a few nanometers in size with quantum phenomena are GQDs. Interestingly, many types of the GQDs have attracted interest due to their outstanding optical characteristics in the presence of photoluminescence involving specific binding capability to a wide range of biomolecules. Such morphological and intrinsic characteristics should serve the analytical transduction of biosensors on the limit of detection (LOD), sensitivity, selectivity, repeatability, and biocompatibility. reduced structure with vacancy defects is RGO, structures a few nanometers in size with quantum phenomena are GQDs. Interestingly, many types of the GQDs have attracted interest due to their outstanding optical characteristics in the presence of photoluminescence involving specific binding capability to a wide range of biomolecules. Such morphological and intrinsic characteristics should serve the analytical transduction of biosensors on the limit of detection (LOD), sensitivity, selectivity, repeatability, and biocompatibility. To provide an understanding of the physics, chemistry, and engineering of graphene-based structures, and how these methods have crucial influences on their characteristic and properties, we will first discuss how graphene and related materials are prepared and synthesized.