An aliphatic thiol ligand of CuInS(2)/ZnS core/shell quantum dots is replaced with a hydroxyl-terminated thiol ligand by utilizing 'on-off state' of ligands during growth stage of the quantum dots. After the ligand-exchange, negligible differences were observed on both photoluminescence spectrum and luminescent quantum efficiency. The reason for the high retention of luminescent efficiency comes from no local agglomeration and no surface deterioration of QDs. It is also observed that 70% of initial ligands are exchanged by the replacing ligand, determined by FT-IR and (1)H NMR. The proposed method provides the quantum dots with an excellent dispersibility in polar solvents, supported by identical luminescence decay characteristics of the QDs.
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http://dx.doi.org/10.1016/j.jcis.2011.06.087 | DOI Listing |
Sci Rep
December 2024
Department of Urology, Urological Science Institute, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-gu, Seoul, 03722, South Korea.
Carbon dots (CDs) are versatile nanomaterials that are considered ideal for application in bioimaging, drug delivery, sensing, and optoelectronics owing to their excellent photoluminescence, biocompatibility, and chemical stability features. Nitrogen doping enhances the fluorescence of CDs, alters their electronic properties, and improves their functional versatility. N-doped CDs can be synthesized via solvothermal treatment of carbon sources with nitrogen-rich precursors; however, systematic investigations of their synthesis mechanisms have been rarely reported.
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December 2024
College of Physical Science and Technology, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
Nanomaterial-biomembrane interactions constitute a critical biological process in assessing the toxicity of such materials in theoretical studies. However, many investigations simplify these interactions by using membrane models containing only one or a few lipid types, deviating significantly from the complexity of real membrane compositions. In particular, cholesterol, a ubiquitous lipid essential for regulating membrane fluidity and closely linked to various diseases, is often overlooked.
View Article and Find Full Text PDFAnal Biochem
December 2024
Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Al-Azhar University, 11751 Nasr City, Cairo, Egypt. Electronic address:
Magnesium is an essential mineral in biological systems and has a significant impact on brain health. Its deficiency has been found to correlate with irregular metabolic processes and neurodevelopmental disorders. The objective of this research was to establish and validate an analytical approach based on the standard addition methodology for determining endogenous magnesium levels in the serum of autistic and healthy children.
View Article and Find Full Text PDFLangmuir
December 2024
Department of Physics, National Institute of Technology, Jamshedpur-831014, India.
We have conducted a systematic study employing density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM) to explore the gas sensing capabilities of nitrogen-doped single vacancy graphene quantum dots (SV/3N) decorated with transition metals (TM = Mn, Co, Cu). We have studied the interactions between TM@SV/3N and four different target gases (AsH, NH, PH, and HS) through the computation of adsorption energies, charge transfer, noncovalent interaction, density of states, band gap, and work function for 12 distinct adsorption systems. Our comprehensive analysis included an in-depth assessment of sensors' stability, sensitivity, selectivity, and reusability for practical applications.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
University of Science and Technology of China, Hefei National Research Center for Physical Sciences at Microscale, jinzhai road, hefei, CHINA.
Herein, we first report a photocatalytic OCM using CO2 as a soft oxidant for C2H6 production under mild conditions, where an efficient photocatalyst with unique interface sites is constructed to facilitate CO2 adsorption and activation, while concurrently boosting CH4 dissociation. As a prototype, the Au quantum dots anchored on oxygen-deficient TiO2 nanosheets are fabricated, where the Au-Vo-Ti interface sites for CO2 adsorption and activation are collectively disclosed by in situ Kelvin probe force microscopy, quasi in situ X-ray photoelectron spectroscopy and theoretical calculations. Compared with single metal site, the Au-Vo-Ti interface sites exhibit the lower CO2 adsorption energy and decrease the energy barrier of the *CO2 hydrogenation step from 1.
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