Two-dimensional crystals with a wealth of exotic dimensional-dependent properties are promising candidates for next-generation ultrathin and flexible optoelectronic devices. For the first time, we demonstrate that few-layered InSe photodetectors, fabricated on both a rigid SiO2/Si substrate and a flexible polyethylene terephthalate (PET) film, are capable of conducting broadband photodetection from the visible to near-infrared region (450-785 nm) with high photoresponsivities of up to 12.3 AW(-1) at 450 nm (on SiO2/Si) and 3.9 AW(-1) at 633 nm (on PET). These photoresponsivities are superior to those of other recently reported two-dimensional (2D) crystal-based (graphene, MoS2, GaS, and GaSe) photodetectors. The InSe devices fabricated on rigid SiO2/Si substrates possess a response time of ∼50 ms and exhibit long-term stability in photoswitching. These InSe devices can also operate on a flexible substrate with or without bending and reveal comparable performance to those devices on SiO2/Si. With these excellent optoelectronic merits, we envision that the nanoscale InSe layers will not only find applications in flexible optoelectronics but also act as an active component to configure versatile 2D heterostructure devices.

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Surface-modified carboxylated nanometre-sized diamond (cND) has been applied for the conjugation of biological molecules such as DNA and protein. In this study, we evaluated the biocompatibility and detection of cNDs and carbon nanotubes on human lung A549 epithelial cells and HFL-1 normal fibroblasts. Treatment with 5 or 100 nm cND particles, 0.1-100 μg ml −1 , did not reduce the cell viability and alter the protein expression profile in lung cells; however, carbon nanotubes induced cytotoxicity in these cells. The cNDs particles were accumulated in A549 cells, which were observed by atomic force microscopy and laser scanning confocal microscopy. Both 5 and 100 nm cNDs particles exhibited the green fluorescence and were ingested into cells. Moreover, the fluorescence intensities were increased in cells via a concentration-dependent manner after treatment with 5 and 100 nm cNDs, which can be detected by flow cytometer analysis. The fluorescence intensities of 5 nm cNDs were relative higher than 100 nm cNDs in cells at equal concentration treatment. The observation demonstrated that cND-interacting with cell is detectable by a confocal microscope, flow cytometer and atomic force microscope. These nanoparticles may be useful for further biomedical applications based on the properties of uptake ability, detectability and little cytotoxicity in human cells.

A novel method is proposed using nanometer-sized diamond particles as detection probes for biolabeling. The advantages of nanodiamond's unique properties were demonstrated in its biocompatibility, nontoxicity, easily detected Raman signal, and intrinsic fluorescence from its natural defects without complicated pretreatments. Carboxylated nanodiamond's (cND's) penetration ability, noncytotoxicity, and visualization of cND-cell interactions are demonstrated on A549 human lung epithelial cells. Protein-targeted cell interaction visualization was demonstrated with cND-lysozyme complex interaction with bacteria Escherichia coli. It is shown that the developed biomolecule-cND complex preserves the original functions of the test protein. The easily detected natural fluorescent and Raman intrinsic signals, penetration ability, and low cytotoxicity of cNDs render them promising agents in multiple medical applications.

Bactericidal activity of traditional titanium dioxide (TiO 2 ) photocatalyst is effective only upon irradiation by ultraviolet light, which restricts the potential applications of TiO 2 for use in our living environments. Recently carbon-containing TiO 2 was found to be photoactive at visible-light illumination that affords the potential to overcome this problem; although, the bactericidal activity of these photocatalysts is relatively lower than conventional disinfectants. Evidenced from scanning electron microscopy and confocal Raman spectral mapping analysis, we found the interaction with bacteria was significantly enhanced in these anatase/rutile mixed-phase carbon-containing TiO 2 . Bacteria-killing experiments indicate that a significantly higher proportion of all tested pathogens including Staphylococcus aureus, Shigella flexneri and Acinetobacter baumannii, were eliminated by the new nanoparticle with higher bacterial interaction property. These findings suggest the created materials with high bacterial interaction ability might be a useful strategy to improve the antimicrobial activity of visible-light-activated TiO 2 .

Articles you may be interested inCommunication: He-tagged vibrational spectra of the SarGlyH+ and H+(H2O)2,3 ions: Quantifying tag effects in cryogenic ion vibrational predissociation (CIVP) spectroscopy Exploring the correlation between network structure and electron binding energy in the ( H 2 O ) 7 − cluster through isomer-photoselected vibrational predissociation spectroscopy and ab initio calculations: Addressing complexity beyond types I-IIIClustering of water on protonated molecular ions has been investigated by vibrational predissociation spectroscopy. Systematic measurements at different cluster sizes reveal a close resemblance of the OH stretch spectra between NH 4 ϩ ͑H 2 O͒ n , CH 3 NH 3 ϩ ͑H 2 O͒ n , and H 3 O ϩ ͑H 2 O͒ n . Particularly at nу6, a sharp feature, identical to that found on ice and water surfaces, emerges at 3690 cm Ϫ1 for free-OH stretching. The feature is distinguished from the other free-OH absorption, commonly observed for small-and medium-sized (H 2 O) n clusters at 3715 cm Ϫ1 . The results, in conjunction with ab initio calculations, provide compelling evidence for 2-and 3-coordinated H 2 O in the protonated ion-water clusters.

This letter presents direct observation of growth hormone receptor in one single cancer cell using nanodiamond-growth hormone complex as a specific probe. The interaction of surface growth hormone receptor of A549 human lung epithelial cells with growth hormone was observed using nanodiamond’s unique spectroscopic signal via confocal Raman mapping. The growth hormone molecules were covalent conjugated to 100nm diameter carboxylated nanodiamonds, which can be recognized specifically by the growth hormone receptors of A549 cell. The Raman spectroscopic signal of diamond provides direct and in vitro observation of growth hormone receptors in physiology condition in a single cell level.

Abstract. Nanometre-sized diamonds (nanodiamonds) are to date the most abundant presolar grains in primitive meteorites. They are therefore presumed to be an abundant component of the dust in the interstellar medium. What then are the expected spectroscopic signatures of these grains in the interstellar medium? In order to answer this question we have examined the infrared spectroscopic properties of the nanodiamonds extracted from the Orgueil meteorite. The nanodiamonds were surfacecleaned and hydrogenated under vacuum. The spectra of the surface C-H stretching features in the 3-5 µm region were then taken. Comparison with larger synthetic nanodiamonds shows that the spectra are size-dependent. The observed meteoritic nanodiamond C-H stretching features are very different from the features seen on the surfaces of larger diamonds (sizes ≥50 nm). Less-processed Orgueil nanodiamonds appear to provide an intriguing similarity to the class B infrared emission band spectra in the 3.3-3.7 µm wavelength region. The spectra of the nanodiamond C-H stretching features can be used as a template in the search for interstellar nanodiamonds in the infrared spectra of astronomical objects. In addition the size-dependence of the nanodiamond surface C-H features can be used to place rigid and robust constraints upon the sizes of these particles in circumstellar media and in the ISM.