Graphene, a two-dimensional, single-layer sheet of sp(2) hybridized carbon atoms, has attracted tremendous attention and research interest, owing to its exceptional physical properties, such as high electronic conductivity, good thermal stability, and excellent mechanical strength. Other forms of graphene-related materials, including graphene oxide, reduced graphene oxide, and exfoliated graphite, have been reliably produced in large scale. The promising properties together with the ease of processibility and functionalization make graphene-based materials ideal candidates for incorporation into a variety of functional materials. Importantly, graphene and its derivatives have been explored in a wide range of applications, such as electronic and photonic devices, clean energy, and sensors. In this review, after a general introduction to graphene and its derivatives, the synthesis, characterization, properties, and applications of graphene-based materials are discussed.

Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications

Owing to their extraordinary electrical, chemical, optical, mechanical and structural properties, graphene and its derivatives have stimulated exploding interests in their sensor applications ever since the first isolation of free-standing graphene sheets in year 2004. This article critically and comprehensively reviews the emerging graphene-based electrochemical sensors, electronic sensors, optical sensors, and nanopore sensors for biological or chemical detection. We emphasize on the underlying detection (or signal transduction) mechanisms, the unique roles and advantages of the used graphene materials. Properties and preparations of different graphene materials, their functionalizations are also comparatively discussed in view of sensor development. Finally, the perspective and current challenges of graphene sensors are outlined (312 references).

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Biological and chemical sensors based on graphene materials

Graphene-based materials are gaining heightened attention as novel materials for environmental applications The unique physicochemical properties of graphene, notably its exceptionally high surface area, electron mobility, thermal conductivity, and mechanical strength, can lead to novel or improved technologies to address the pressing global environmental challenges This critical review assesses the recent developments in the use of graphene-based materials as sorbent or photocatalytic materials for environmental decontamination, as building blocks for next generation water treatment and desalination membranes, and as electrode materials for contaminant monitoring or removal The most promising areas of research are highlighted, with a discussion of the main challenges that we need to overcome in order to fully realize the exceptional properties of graphene in environmental applications

Environmental applications of graphene-based nanomaterials.

Recent advances in graphene-based biosensors

Adsorption of heavy metals on conventional and nanostructured materials for wastewater treatment purposes: A review

Chelating groups are successfully linked to graphene oxide (GO) surfaces through a silanization reaction between N-(trimethoxysilylpropyl) ethylenediamine triacetic acid (EDTA-silane) and hydroxyl groups on GO surface. EDTA-GO was found to be an ideal adsorbent for Pb(II) removal with a higher adsorption capacity. EDTA-modification enhances the adsorption capacity of GO because of the chelating ability of ethylene diamine triacetic acid. This study investigates the adsorption and desorption behaviors of heavy metal cations and the effects of solution conditions such as pH on Pb(II) removal. The adsorption capacity for Pb(II) removal was found to be 479 ± 46) mg/g at pH 6.8, and the adsorption process was completed within 20 min. The Langmuir adsorption model agrees well with the experimental data. The experimental results suggest that EDTA-GO can be reused after washed with HCl, suggesting potential applications in the environmental cleanup.

Adsorption Behavior of EDTA-Graphene Oxide for Pb (II) Removal

Formation of highly stable dispersions of silane-functionalized reduced graphene oxide

A new type of chemically modified graphene, EDTA-modified reduced graphene (EDTA-RG), was synthesized by silanization of graphene with N-(trimethoxysilylpropyl) ethylenediamine triacetic acid (EDTA-silane). It was found that the presence of EDTA on the graphene surface enables the formation of a very stable suspension of EDTA-RG in Nafion/ethanol solution. When deposited onto a glass carbon electrode surface, a very stable, uniform thin film of EDTA-RG−Nafion composite was successfully obtained. The electrochemical behavior of this EDTA-RG−Nafion modified electrode, electrochemical catalysis, ionic selectivity, and biocompatibility, have been investigated using a variety of electrochemical techniques. The ion selectivity was investigated by using a negatively charged probe [Fe(CN)6]3−/4−, a positively charged probe, Ru(bpy)32+, and two biomolecules, dopamine and ascorbic acid. The thin film of EDTA-RG−Nafion composite exhibits high ion selectivity. Performances of EDTA−graphene−Nafion modified electrodes ...

Highly Sensitive and Selective Dopamine Biosensor Fabricated with Silanized Graphene

Platinum nanoparticles anchored on chelating group-modified graphene for methanol oxidation

Ab initio 6-31G(d) and MP2/6-31G(d)//6-31G(d) methods were used to calculate the energies of the rotamers of the chair conformers of alkylcyclohexanes and trimethylsilylcyclohexane. The MP2/6-31G(d)//6-31G(d) calculated conformational energies ( or A values, in kcal/mol) of the alkylcyclohexanes (Me = 1.96; Et = 1.80; Pr = 1.73 iso-Pr = 1.60; t-Bu = 5.45; neo-pent = 1.32) and trimethylsilylcyclohexane (SiMe3 = 2.69) are similar to the experimental values. Plots of the calculated conformational energies for the alkylcyclohexanes and trimethylsilylcyclohexane versus their experimental values are linear (slope = 1.253 and r = .993 for 6-31G(d) and slope = 1.114 and r = .982 for MP2/6-31G(d)//6-31G(d)). The conformational energies are determined primarily by steric effects which include gauche (synclinal) interactions and repulsive nonbonded interactions in both the axial and equatorial conformers.

Marc L. Kasner

Papers

Adsorption Behavior of EDTA-Graphene Oxide for Pb (II) Removal

Formation of highly stable dispersions of silane-functionalized reduced graphene oxide

Highly Sensitive and Selective Dopamine Biosensor Fabricated with Silanized Graphene

Platinum nanoparticles anchored on chelating group-modified graphene for methanol oxidation

A Comparison of the ab Initio Calculated and Experimental Conformational Energies of Alkylcyclohexanes