and Applications of Fullerenes, Carbon Dots, Nanotubes, Graphene, Nanodiamonds, and Combined Superstructures Vasilios Georgakilas,† Jason A. Perman,‡ Jiri Tucek,‡ and Radek Zboril*,‡ †Material Science Department, University of Patras, 26504 Rio Patras, Greece ‡Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University in Olomouc, 17 listopadu 1192/12, 771 46 Olomouc, Czech Republic

Broad family of carbon nanoallotropes: classification, chemistry, and applications of fullerenes, carbon dots, nanotubes, graphene, nanodiamonds, and combined superstructures.

Carbon Nanomaterials for Biological Imaging and Nanomedicinal Therapy

Applications of Supramolecular Anion Recognition

The possibility to change the molecular assembled structures of organic and organometallic materials through mechanical stimulation is emerging as a general and powerful concept for the design of functional materials. In particular, the photophysical properties such as photoluminescence color, quantum yield, and emission lifetime of organic and organometallic fluorophores can significantly depend on the molecular packing, enabling the development of molecular materials with mechanoresponsive luminescence characteristics. Indeed, an increasing number of studies have shown in recent years that mechanical force can be utilized to change the molecular arrangement, and thereby the optical response, of luminescent molecular assemblies of π-conjugated organic or organometallic molecules. Here, the development of such mechanoresponsive luminescent (MRL) molecular assemblies consisting of organic or organometallic molecules is reviewed and emerging trends in this research field are summarized. After a brief introduction of mechanoresponsive luminescence observed in molecular assemblies, the concept of "luminescent molecular domino" is introduced, before molecular materials that show turn-on/off of photoluminescence in response to mechanical stimulation are reviewed. Mechanically stimulated multicolor changes and water-soluble MRL materials are also highlighted and approaches that combine the concept of MRL molecular assemblies with other materials types are presented in the last part of this progress report.

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Mechanoresponsive Luminescent Molecular Assemblies: An Emerging Class of Materials

Photoresponsive Host–Guest Functional Systems

Smart luminescent materials that are responsive to external stimuli have received considerable interest. Here we report ionic iridium (III) complexes simultaneously exhibiting mechanochromic, vapochromic and electrochromic phosphorescence. These complexes share the same phosphorescent iridium (III) cation with a N-H moiety in the N^N ligand and contain different anions, including hexafluorophosphate, tetrafluoroborate, iodide, bromide and chloride. The anionic counterions cause a variation in the emission colours of the complexes from yellow to green by forming hydrogen bonds with the N-H proton. The electronic effect of the N-H moiety is sensitive towards mechanical grinding, solvent vapour and electric field, resulting in mechanochromic, vapochromic and electrochromic phosphorescence. On the basis of these findings, we construct a data-recording device and demonstrate data encryption and decryption via fluorescence lifetime imaging and time-gated luminescence imaging techniques. Our results suggest that rationally designed phosphorescent complexes may be promising candidates for advanced data recording and security protection.

/pdf/smart-responsive-phosphorescent-materials-for-data-recording-4o8823he6n.pdf

Smart responsive phosphorescent materials for data recording and security protection

Graphene, because of its excellent mechanical, electrical, chemical, physical properties, sparked great interest to develop and extend its applications. Particularly, graphene based field-effect transistors (GFETs) present exciting and bright prospects for sensing applications due to their greatly higher sensitivity and stronger selectivity. This Review highlights a selection of important topics pertinent to GFETs and their application in electronic sensors. This article begins with a description of the fabrications and characterizations of GFETs, and then introduces the new developments in physical, chemical, and biological electronic detection using GFETs. Finally, several perspective and current challenges of GFETs development are presented, and some proposals are suggested for further development and exploration.

Graphene field-effect transistor and its application for electronic sensing.

The application of a time-resolved photoluminescence technique and fluorescence lifetime imaging microscopy for biosensing and bioimaging based on phosphorescent conjugated polyelectrolytes (PCPEs) containing Ir(III) complexes and polyfluorene units is reported. The specially designed PCPEs form 50 nm nanoparticles with blue fluorescence in aqueous solutions. Electrostatic interaction between the nanoparticles and heparin improves the energy transfer between the polyfluorene units to Ir(III) complex, which lights up the red signal for naked-eye sensing. Good selectivity has been demonstrated for heparin sensing in aqueous solution and serum with quantification ranges of 0–70 μM and 0–5 μM, respectively. The signal-to-noise ratio can be further improved through time-resolved emission spectra, especially when the detection is conducted in complicated environment, e.g., in the presence of fluorescent dyes. In addition to heparin sensing, the PCPEs have also been used for specific labeling of live KB cell membrane with high contrast using both confocal fluorescent cellular imaging and fluorescence lifetime imaging microscopies. This study provides a new perspective for designing promising CPEs for biosensing and bioimaging applications.

Cationic Polyfluorenes with Phosphorescent Iridium(III) Complexes for Time‐Resolved Luminescent Biosensing and Fluorescence Lifetime Imaging

Resveratrol (RSV), a polyphenol, is known to play an important role in inhibiting proliferation and inducing apoptosis of glioma cells. The aim of this study was to explore the mechanism of RSV on U251 cells apoptosis. RSV showed a dose-dependent decrease in U251 cell viability. It could reduce IκB phosphorylation, nuclear P65 protein levels and NF-κB transcriptional activity, which suggested that signaling pathway are involved in RSV-induced apoptosis. In addition, RSV could inhibit miR-21 expression and down-regulation of miR-21 expression could suppress NF-κB activity. Interestingly, over-expression of miR-21 can reverse the effect of RSV on NF-κB activity and apoptosis in U251 cells. These results suggest that RSV can effectively induce apoptosis of U251 cells and modulation of miR-21 possibly contributes to this antitumor action.

Resveratrol repressed viability of U251 cells by miR-21 inhibiting of NF-κB pathway.

Biosensing and Bioimaging: Cationic Polyfluorenes with Phosphorescent Iridium(III) Complexes for Time-Resolved Luminescent Biosensing and Fluorescence Lifetime Imaging (Adv. Funct. Mater. 26/2013)

Gareth Jenkins

Papers

Smart responsive phosphorescent materials for data recording and security protection

Graphene field-effect transistor and its application for electronic sensing.

Cationic Polyfluorenes with Phosphorescent Iridium(III) Complexes for Time‐Resolved Luminescent Biosensing and Fluorescence Lifetime Imaging

Resveratrol repressed viability of U251 cells by miR-21 inhibiting of NF-κB pathway.

Biosensing and Bioimaging: Cationic Polyfluorenes with Phosphorescent Iridium(III) Complexes for Time-Resolved Luminescent Biosensing and Fluorescence Lifetime Imaging (Adv. Funct. Mater. 26/2013)