Similar to its popular older cousins the fullerene, the carbon nanotube, and graphene, the latest form of nanocarbon, the carbon nanodot, is inspiring intensive research efforts in its own right. These surface-passivated carbonaceous quantum dots, so-called C-dots, combine several favorable attributes of traditional semiconductor-based quantum dots (namely, size- and wavelength-dependent luminescence emission, resistance to photobleaching, ease of bioconjugation) without incurring the burden of intrinsic toxicity or elemental scarcity and without the need for stringent, intricate, tedious, costly, or inefficient preparation steps. C-dots can be produced inexpensively and on a large scale (frequently using a one-step pathway and potentially from biomass waste-derived sources) by many approaches, ranging from simple candle burning to in situ dehydration reactions to laser ablation methods. In this Review, we summarize recent advances in the synthesis and characterization of C-dots. We also speculate on their future and discuss potential developments for their use in energy conversion/storage, bioimaging, drug delivery, sensors, diagnostics, and composites.

Luminescent Carbon Nanodots: Emergent Nanolights

Fluorescent carbon nanoparticles or carbon quantum dots (CQDs) are a new class of carbon nanomaterials that have emerged recently and have garnered much interest as potential competitors to conventional semiconductor quantum dots. In addition to their comparable optical properties, CQDs have the desired advantages of low toxicity, environmental friendliness low cost and simple synthetic routes. Moreover, surface passivation and functionalization of CQDs allow for the control of their physicochemical properties. Since their discovery, CQDs have found many applications in the fields of chemical sensing, biosensing, bioimaging, nanomedicine, photocatalysis and electrocatalysis. This article reviews the progress in the research and development of CQDs with an emphasis on their synthesis, functionalization and technical applications along with some discussion on challenges and perspectives in this exciting and promising field.

Carbon quantum dots and their applications

Approaches, Derivatives and Applications Vasilios Georgakilas,† Michal Otyepka,‡ Athanasios B. Bourlinos,‡ Vimlesh Chandra, Namdong Kim, K. Christian Kemp, Pavel Hobza,‡,§,⊥ Radek Zboril,*,‡ and Kwang S. Kim* †Institute of Materials Science, NCSR “Demokritos”, Ag. Paraskevi Attikis, 15310 Athens, Greece ‡Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo naḿ. 2, 166 10 Prague 6, Czech Republic

Functionalization of Graphene: Covalent and Non-Covalent Approaches, Derivatives and Applications

I read this book the same weekend that the Packers took on the Rams, and the experience of the latter event, obviously, colored my judgment. Although I abhor anything that smacks of being a handbook (like, \"How to Earn a Merit Badge in Neurosurgery\") because too many volumes in biomedical science already evince a boyscout-like approach, I must confess that parts of this volume are fast, scholarly, and significant, with certain reservations. I like parts of this well-illustrated book because Dr. Sj6strand, without so stating, develops certain subjects on technique in relation to the acquisition of judgment and sophistication. And this is important! So, given that the author (like all of us) is somewhat deficient in some areas, and biased in others, the book is still valuable if the uninitiated reader swallows it in a general fashion, realizing full well that what will be required from the reader is a modulation to fit his vision, propreception, adaptation and response, and the kind of problem he is undertaking. A major deficiency of this book is revealed by comparison of its use of physics and of chemistry to provide understanding and background for the application of high resolution electron microscopy to problems in biology. Since the volume is keyed to high resolution electron microscopy, which is a sophisticated form of structural analysis, but really morphology in a modern guise, the physical and mechanical background of The instrument and its ancillary tools are simply and well presented. The potential use of chemical or cytochemical information as it relates to biological fine structure , however, is quite deficient. I wonder when even sophisticated morphol-ogists will consider fixation a reaction and not a technique; only then will the fundamentals become self-evident and predictable and this sine qua flon will become less mystical. Staining reactions (the most inadequate chapter) ought to be something more than a technique to selectively enhance contrast of morphological elements; it ought to give the structural addresses of some of the chemical residents of cell components. Is it pertinent that auto-radiography gets singled out for more complete coverage than other significant aspects of cytochemistry by a high resolution microscopist, when it has a built-in minimal error of 1,000 A in standard practice? I don't mean to blind-side (in strict football terminology) Dr. Sj6strand's efforts for what is \"routinely used in our laboratory\"; what is done is usually well done. It's just that …

Methods in Enzymology.

Fluorescent carbon-based materials have drawn increasing attention in recent years owing to exceptional advantages such as high optical absorptivity, chemical stability, biocompatibility, and low toxicity. These materials primarily include carbon dots (CDs), nanodiamonds, carbon nanotubes, fullerene, and fluorescent graphene. The superior properties of fluorescent carbon-based materials distinguish them from traditional fluorescent materials, and make them promising candidates for numerous exciting applications, such as bioimaging, medical diagnosis, catalysis, and photovoltaic devices. Among all of these materials, CDs have drawn the most extensive notice, owing to their early discovery and adjustable parameters. However, many scientific issues with CDs still await further investigation. Currently, a broad series of methods for obtaining CD-based materials have been developed, but efficient one-step strategies for the fabrication of CDs on a large scale are still a challenge in this field. Current synthetic methods are mainly deficient in accurate control of lateral dimensions and the resulting surface chemistry, as well as in obtaining fluorescent materials with high quantum yields (QY). Moreover, it is important to expand these kinds of materials to novel applications. Herein, a facile and highoutput strategy for the fabrication of CDs, which is suitable for industrial-scale production (yield is ca. 58%), is discussed. The QY was as high as ca. 80%, which is the highest value recorded for fluorescent carbon-based materials, and is almost equal to fluorescent dyes. The polymer-like CDs were converted into carbogenic CDs by a change from low to high synthesis temperature. The photoluminescence (PL) mechanism (high QY/PL quenching) was investigated in detail by ultrafast spectroscopy. The CDs were applied as printing ink on the macro/micro scale and nanocomposites were also prepared by polymerizing CDs with certain polymers. Additionally, the CDs could be utilized as a biosensor reagent for the detection of Fe in biosystems. The CDs were prepared by a hydrothermal method, which is described in the Supporting Information (Figure 1a; see also the Supporting Information, Figure S1). The reaction was conducted by first condensing citric acid and ethylenediamine, whereupon they formed polymer-like CDs, which were then carbonized to form the CDs. The morphology and structure of CDs were confirmed by analysis. Figure 1b shows transmission electron microscopy (TEM) images of the CDs, which can be seen to have a uniform dispersion without apparent aggregation and particle diameters of 2–6 nm. The sizes of CDs were also measured by atomic force microscopy (AFM; Figure S2), and the average height was 2.81 nm. From the high-resolution TEM, most particles are observed to be amorphous carbon particles without any lattices; rare particles possess well-resolved lattice fringes. With such a low carbon-lattice-structure content, no obvious D or G bands were detected in the Raman spectra of the CDs (Figure S3). The XRD patterns of the CDs (Figure 1c) also displayed a broad peak centered at 258 (0.34 nm), which is also attributed to highly disordered carbon atoms. Moreover, NMR spectroscopy (H and C) was employed to distinguish sp-hybridized carbon atoms from sp-hybridized carbon atoms (Figure S4). In the H NMR spectrum, sp carbons were detected. In the C NMR spectrum, signals in the range of 30–45 ppm, which correspond to aliphatic (sp) carbon atoms, and signals from 100–185 ppm, which are indicative of sp carbon atoms, were observed. Signals in the range of 170– 185 ppm, which correspond to carboxyl/amide groups, were also present. In the FTIR analysis of CDs, the following were observed: stretching vibrations of C OH at 3430 cm 1 and C H at 2923 cm 1 and 2850 cm , asymmetric stretching vibrations of C-NH-C at 1126 cm , bending vibrations of N H at 1570 cm , and the vibrational absorption band of C=O at 1635 cm 1 (Figure S5). Moreover, the surface groups were also investigated by XPS analysis (Figure 1d). C1s analysis revealed three different types of carbon atoms: graphitic or aliphatic (C=C and C C), oxygenated, and nitrous (Table S1). In the UV/Vis spectra, the peak was focused on 344 nm in an aqueous solution of CDs. In the fluorescence spectra, CDs have optimal excitation and emission wavelengths at 360 nm and 443 nm, and show a blue color under a hand-held UV lamp (Figure 2a). Excitation-dependent PL behavior was [*] S. Zhu, Q. Meng, Prof. J. Zhang, Y. Song, Prof. K. Zhang, Prof. B. Yang State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University Changchun, 130012 (P. R. China) E-mail: byangchem@jlu.edu.cn

Highly Photoluminescent Carbon Dots for Multicolor Patterning, Sensors, and Bioimaging

Within the last decade, ionic liquids have come to the fore as environmentally-responsible designer solvents. But what are ionic liquids and what can they offer the analytical scientist? This article addresses these questions and chronicles recent progress made in the application of ionic liquids toward analytical problem-solving. While further progress is required before ionic liquids become mainstream analytical solvents, results to date commend their use in various modes of chemical analysis. It is our aim that the findings reported herein draw other researchers into this area and encourage the increased application of ionic liquids in this manner.

Sheila N. Baker

Papers

Luminescent Carbon Nanodots: Emergent Nanolights

An analytical view of ionic liquids

The large scale synthesis of pure imidazolium and pyrrolidinium ionic liquids

Luminescent Carbon Nanodots: Emergent Nanolights

Fluorescence studies of protein thermostability in ionic liquids