The Experts below are selected from a list of 107496 Experts worldwide ranked by ideXlab platform
Yang Tian - One of the best experts on this subject based on the ideXlab platform.
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carbon dot based ratiometric fluorescent probe for imaging and biosensing of superoxide anion in live cells
Analytical Chemistry, 2014Co-Authors: Xiang Gao, Anwei Zhu, Changqin Ding, Yang TianAbstract:In this article, a ratiometric fluorescent biosensor for O2•– was developed, by employing carbon dots (C-Dots) as the reference fluorophore and hydroethidine (HE), a specific organic molecule toward O2•–, playing the role as both specific recognition element and response signal. The hybrid fluorescent probe CD-HE only emitted at 525 nm is ascribed to C-Dots, while HE was almost nonfluorescent, upon excitation at 488 nm. However, after reaction with O2•–, a new Emission Peak ascribed to the reaction products of HE and O2•– was clearly observed at 610 nm. Meanwhile, this Peak gradually increased with the increasing concentration of O2•– but the Emission Peak at 525 nm stayed constant, leading to a ratiometric detection of O2•–. The inorganic–organic fluorescent sensor exhibited high sensitivity, a broad dynamic linear range of ∼5 × 10–7–1.4 × 10–4 M, and low detection limit down to 100 nM. The present probe also showed high accuracy and excellent selectivity for O2•– over other reactive oxygen species (ROS)...
Yuequn Shang - One of the best experts on this subject based on the ideXlab platform.
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colloidal quantum dots surface and device structure engineering for high performance light emitting diodes
National Science Review, 2017Co-Authors: Yuequn Shang, Zhijun NingAbstract:The application of colloidal quantum dots for light-emitting devices has attracted considerable attention in recent years, due to their unique optical properties such as size-dependent Emission wavelength, sharp Emission Peak and high luminescent quantum yield. Tremendous efforts have been made to explore quantum dots for light-Emission applications such as light-emitting diodes (LEDs) and light converters. The performance of quantum-dots-based light-emitting diodes (QD-LEDs) has been increasing rapidly in recent decades as the development of quantum-dots synthesis, surface-ligand engineering and device-architecture optimization. Recently, the external quantum efficiencies of red quantum-dots LEDs have exceeded 20.5% with good stability and narrow Emission Peak. In this review, we summarize the recent advances in QD-LEDs, focusing on quantum-dot surface engineering and device-architecture optimization.
Fei Zhao - One of the best experts on this subject based on the ideXlab platform.
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Quantum Dots for Wide Color Gamut Displays from Photoluminescence to Electroluminescence
Nanoscale Research Letters, 2017Co-Authors: Yongyin Kang, Yehua Su, Zhicheng Song, Xia Yin, Long Fang, Xiaofang Jiang, Jing Gao, Fei ZhaoAbstract:Monodisperse quantum dots (QDs) were prepared by low-temperature process. The remarkable narrow Emission Peak of the QDs helps the liquid crystal displays (LCD) and electroluminescence displays (QD light-emitting diode, QLED) to generate wide color gamut performance. The range of the color gamut for QD light-converting device (QLCD) is controlled by both the QDs and color filters (CFs) in LCD, and for QLED, the optimized color gamut is dominated by QD materials.
Hajime Haneda - One of the best experts on this subject based on the ideXlab platform.
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band edge Emission of undoped and doped zno single crystals at room temperature
Journal of Applied Physics, 2002Co-Authors: Naoki Ohashi, Takashi Sekiguchi, Kouichiroh Aoyama, Takeshi Ohgaki, Yoshihiro Terada, Isao Sakaguchi, Takaaki Tsurumi, Hajime HanedaAbstract:Band-edge Emission of ZnO at around room temperature was investigated by measuring the temperature dependence of cathodoluminescence spectra at 20–300 K. Undoped crystals grown by a vapor transport method and Al-doped crystals by flux method were employed to elucidate the effect of doping on luminescence properties. For the Al-doped crystals, the free-exciton Emission was weak through out the temperature range T<300 K. The most intense Emission Peak of the Al-doped crystal was energetically close to bound exciton annihilation Emission. On the other hand, for undoped crystals, it was found that the most intense Emission Peak at room temperature was at E≈Eg−60 meV and this Peak was not assignable to free-exciton annihilation Emission. It was also found that this Peak is not a reason for the reduction in Emission efficiency.
Suresh Kumar Kailasa - One of the best experts on this subject based on the ideXlab platform.
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designing of glutathione lactose derivative for the fabrication of gold nanoclusters with red fluorescence sensing of al3 and cu2 ions with two different mechanisms
Optical Materials, 2020Co-Authors: Mehul R Kateshiya, Naved I Malek, Z V P Murthy, Suresh Kumar KailasaAbstract:Abstract In this work, a simple and novel glutathione-lactose (GSH-lactose) derivative was synthesized and used as a template for the fabrication of fluorescent gold nanoclusters (GSH-lactose-AuNCs). The synthesized fluorescent GSH-lactose-AuNCs were stable and showed red Emission color by irradiating with 365 nm of UV light. At 410 nm of excitation wavelength, the fluorescent GSH-lactose-AuNCs exhibited a strong Emission Peak at 635 nm. The fluorescent GSH-lactose-AuNCs acted as a fluorescent sensor for the rapid and sensitive detection of two metal ions i.e., Al3+ and Cu2+ ions with different sensing mechanisms such as fluorescence enhancement for Al3+ ion and fluorescence quenching for Cu2+ ion). As a result, the Emission Peak of GSH-lactose-AuNCs at 635 nm exhibited independent behaviour i.e., a linear enhancement with the addition of Al3+ ion and a linear quenching efficiency with Cu2+ ion. Thus, good linear relationships were noticed between intensity (I and I0/I) over the concentration ranges of 0.075–100 μM for Al3+ ion and of 0.050–100 μM for Cu2+ ion with correlations coefficients of 0.9962 and 0.9964. The detection limits are 12 and 52 nM for Al3+ and Cu2+ ions. The GSH-lactose-AuNCs-based analytical approach was successfully applied to quantify Al3+ and Cu2+ ions in real samples.
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facile green synthesis of carbon dots from pyrus pyrifolia fruit for assaying of al3 ion via chelation enhanced fluorescence mechanism
Journal of Molecular Liquids, 2018Co-Authors: Jigna R Bhamore, Sanjay Jha, Rakesh Kumar Singhal, Tae Jung Park, Suresh Kumar KailasaAbstract:Abstract In this work, we synthesized fluorescent carbon dots (CDs) using Pyrus pyrifolia (pear) fruit via hydrothermal method at 180 °C for 6 h without using any further treatment or surface passivating agents. The synthesized CDs possess intense blue fluorescence under UV lamp at 365 nm and exhibit Emission Peak at 471 nm when excited at 390 nm. Because of specific surface functional groups, the synthesized CDs showed high selectivity to detect Al3+ ion through chelation enhanced fluorescence (CHEF) mechanism. The Emission Peak intensity of CDs at 471 nm was gradually enhanced with increasing concentration of Al3+ ion, thereby Al3+ ion was quantified by plotting calibration curve over the range of 0.005–50 μM with a detection limit of 0.0025 μM (2.5 nM). The nanoprobe was subsequently evaluated by assaying Al3+ ion from spiked water samples, signifying the utility of nanoprobe for assaying of Al3+ ion real samples. Furthermore, we also demonstrate that the bioimaging ability of CDs for imaging of Bacillus subtilis bacterial cell, suggesting that the nanoprobe can be used for cell imaging applications.
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one step green synthetic approach for the preparation of multicolor emitting copper nanoclusters and their applications in chemical species sensing and bioimaging
Biosensors and Bioelectronics, 2016Co-Authors: Jigna R Bhamore, Sanjay Jha, Anil Kumar Mungara, Rakesh Kumar Singhal, Dhanshri Sonkeshariya, Suresh Kumar KailasaAbstract:One-step green microwave synthetic approach was developed for the synthesis of copper nanoclusters (Cu NCs) and used as a fluorescent probe for the sensitive detection of thiram and paraquat in water and food samples. Unexpectedly, the prepared Cu NCs exhibited strong orange fluorescence and showed Emission Peak at 600 nm, respectively. Under optimized conditions, the quenching of Cu NCs Emission Peak at 600 nm was linearly proportional to thiram and paraquat concentrations in the ranges from 0.5 to 1000 µM, and from 0.2 to 1000 µM, with detection limits of 70 nM and 49 nM, respectively. In addition, bioimaging studies against Bacillus subtilis through confocal fluorescence microscopy indicated that Cu NCs showed strong blue and green fluorescence signals, good permeability and minimum toxicity against the various bacteria species, which demonstrates their potential feasibility for chemical species sensing and bioimaging applications.