Institute of Chemistry
Changchun Institute of Applied Chemistry, Chinese Academy Of SciencesNot a member yet
23443 research outputs found
Sort by
Fine-tuning the LSPR response of gold nanorod-polyaniline core-shell nanoparticles with high photothermal efficiency for cancer cell ablation
No full textGold nanorods (GNRs) with suitable aspect ratios have strong localized surface plasmon resonance (LSPR) absorption and scattering in the 650-900 nm near-infrared region, which make them attractive for in vitro or in vivo imaging and photothermal cancer therapy. However, they often suffer from cytotoxicity and instability for practical applications, and therefore need further surface modification to solve these issues. In this study, GNRs coated with biocompatible polyaniline (PANI) were used as a stable and highly efficient photothermal agent for cancer cell ablation. Fine-tuning the LSPR response of the GNR-PANI core-shell nanoparticles via thickness-controlled coating of the PANI nanoshells, optimizes the photothermal conversion efficiency of the agent. As a result of the contributions from the GNR core and PANI shell, the capability of photothermal transduction of the resultant nanoparticles at 808 nm is greatly enhanced. After exposure to a continuous NIR laser at 808 nm for similar to 5 min, cancer cells were efficiently ablated requiring only a very low laser flux of 0.6 W cm(-2), the lowest value reported to date for plasmonic nanostructures, showing the great potential for photothermal cancer therapy
High-efficiency immunoassay platforms with controllable surface roughness and oriented antibody immobilization
No full textHigh-efficiency immunoassay platforms with controlled surface roughness (single-and dual-scale structured surface) were prepared by combining a facile layer-by-layer particle deposition approach with oriented immobilization of antibodies through boronic acid moieties. The as-prepared surfaces showed significantly enhanced antibody loading capacity and antigen recognition, as proved by fluorescence images
Preparation of a C-70 Bis-heterocyclic Derivative with High Chemio- and Regioselectivity
No full textC-70 bis-heterocyclic derivative (1) bearing one oxazoline ring and one imidazoline ring with the 2 o'clock configuration is obtained with high chemio- and regioselectivity via the reaction of C-70 with hydroxide and benzonitrile quenched with I-2. Further study with benzylation experiment and theoretical calculations indicate that the oxazoline ring is the one first formed on the C-70 cage, while the imidazoline ring is the one formed after the addition of I-2 via a radical coupling reaction mechanism
Starburst 4,4 ',4 '''-tris(carbazol-9-yl)-triphenylamine-based deep-blue fluorescent emitters with tunable oligophenyl length for solution-processed undoped organic light-emitting diodes
No full textOn the basis of a well-known hole transporting material, namely 4,4',4 ''-tris(carbazol-9-yl)-triphenylamine (TCTA), a series of star-shaped deep-blue fluorescent emitters (2P-TCTA, 3P-TCTA, 4P-TCTA and 5P-TCTA) have been successfully developed via a simple extension of the oligophenyl chain between two N atoms. When the number of phenyl rings increases, it is found that both the absorption and emission for these TCTA-based starbursts are red-shifted and finally become saturated for 5P-TCTA consisting of a pentaphenyl bridge. Interestingly, on going from 2P-TCTA to 5P-TCTA, the film photoluminescence quantum yield is gradually enhanced from 11.4% to 35.5%. The same trend is also observed for their corresponding solution-processed undoped OLEDs. As a consequence, 5P-TCTA shows the best device performance, revealing a maximum luminescence of 7300 cd m(-2), and a peak luminous efficiency of 2.48 cd A(-1) (2.15 lm W-1; 2.30%) together with CIE coordinates of (0.15, 0.09)
Reduced efficiency roll-off in all-phosphorescent white organic light-emitting diodes with an external quantum efficiency of over 20%
No full textAlthough previously reported all-phosphorescent white organic light-emitting diodes (WOLEDs) exhibit impressive electroluminescence efficiencies, problems remain in terms of the severe efficiency roll-off at high brightness. Here, a smart design of the emissive zone structure is presented to make full use of generated excitons to realize high efficiency all-phosphorescent WOLEDs with reduced efficiency roll-off. The fabricated WOLED shows a maximum power efficiency (PE) of 46.6 lm W-1, a current efficiency (CE) of 46.4 cd A(-1) and an external quantum efficiency (EQE) of 22.4%. These values remain as high as 41.3 lm W-1, 46.2 cd A(-1) and 22.0%, respectively, at a brightness of 1000 cd m(-2), exhibiting less pronounced efficiency roll-off. The critical current density, where the EQE declines by half from its peak, reaches 220 mA cm(-2), which should be a high value for all-phosphorescent WOLEDs with an external quantum efficiency of over 20%
Photoluminescence properties of single-component white-emitting Ca9Bi(PO4)(7):Ce3+,Tb3+,Mn2+ phosphors for UV LEDs
No full textCo-doping of Ce3+/Eu2+, Tb3+, Mn2+ ions into a single-component host is commonly used to achieve white-light phosphors through energy transfer, which present good color stability and high color rendering index (CRI) values. In this work, a series of single-component trichromatic white-light-emitting Ca9Bi(PO4)(7)(CBPO):Ce3+, Tb3+, Mn2+ phosphors were synthesized and investigated. The crystal structure, luminescence properties and energy transfer behavior are discussed in detail. The energy transfer process from Ce3+ to Tb3+/Mn2+ has been demonstrated to be a resonant type via the dipole-dipole-quadrupole-quadrupole interaction mechanism, respectively, which makes the emission color shift from purple-blue to green/red with the corresponding Commission Internationale de L'Eclairage (CIE) chromaticity coordinates from (0.166, 0.011) to (0.260, 0.569) and (0.582, 0.287), respectively. Additionally, the white light emission by controlling the concentration ratio of Tb3+ and Mn2+ ions has been acquired in the CBPO:0.08Ce(3+), 0.22Tb(3+), 0.11Mn(2+) sample with the CIE chromaticity coordinates of (0.375, 0.310) and an absolute quantum yield of 50% upon 292 nm excitation. The maximum quantum yield is 84% for CBPO:0.08Ce(3+), 0.90Tb(3+). The good thermal stability of the CBPO:0.08Ce(3+), 0.22Tb(3+), 0.11Mn(2+) sample shows about 83.6% at 150 degrees C of its initial PL intensity at room temperature, which attracts more attention. The results suggest that the present phosphors can be potentially applied as candidates of single-component white-light phosphors for UV-pumped w-LEDs
Donor-acceptor-donor conjugated oligomers based on isoindigo and anthra[1,2-b]thieno[2,3-d]thiophene for organic thin-film transistors: the effect of the alkyl side chain length on semiconducting properties
No full textThree donor-acceptor-donor (D-A-D) conjugated oligomers, i.e., 2ATT-IID-C8C10, 2ATT-IID-C6C8 and 2ATT-IID-C4C6, have been synthesized using anthra[1,2-b]thieno[2,3-d]thiophene (ATT) as an electron-donor unit and isoindigo (IID) as an electron-acceptor unit by combining the planar and rigid structure of fused aromatics and the strong intramolecular interaction of D-A conjugated molecules, and their semiconducting properties were studied via organic thin-film transistors (OTFTs). The alkyl chains, which are 2-octyldodecyl (C8C10), 2-hexyldecyl (C6C8) and 2-butyloctyl (C4C6), respectively, were employed in the IID unit in order to study the effect of alkyl bulkiness on the properties of the oligomers. All three oligomers adopted an edge-on alignment in thin films. Decreasing the bulkiness or length of the alkyls caused a noticeable improvement of the packing order of the oligomers, leading to a remarkably enhanced charge carrier mobility. 2ATT-IID-C8C10 could only form the film featured with one-dimensional order. Consequently, it exhibited the lowest OTFT mobility (<0.1 cm(2) V-1 s(-1)). In contrast, both 2ATT-IID-C6C8 and 2ATT-IID-C4C6 adopted two-dimensional-ordered packing structures after thermal annealing with a pi-pi stacking distance of similar to 3.6 angstrom, thereby exhibiting promising semiconducting properties. 2ATT-IID-C4C6 showed the best OTFT performance with a mobility of 0.72 cm(2) V-1 s(-1). This mobility is among the highest for the solution processible D-A conjugated oligomers to date
The Universal Statistical Distributions of the Affinity, Equilibrium Constants, Kinetics and Specificity in Biomolecular Recognition
No full textWe uncovered the universal statistical laws for the biomolecular recognition/binding process. We quantified the statistical energy landscapes for binding, from which we can characterize the distributions of the binding free energy (affinity), the equilibrium constants, the kinetics and the specificity by exploring the different ligands binding with a particular receptor. The results of the analytical studies are confirmed by the microscopic flexible docking simulations. The distribution of binding affinity is Gaussian around the mean and becomes exponential near the tail. The equilibrium constants of the binding follow a log-normal distribution around the mean and a power law distribution in the tail. The intrinsic specificity for biomolecular recognition measures the degree of discrimination of native versus non-native binding and the optimization of which becomes the maximization of the ratio of the free energy gap between the native state and the average of non-native states versus the roughness measured by the variance of the free energy landscape around its mean. The intrinsic specificity obeys a Gaussian distribution near the mean and an exponential distribution near the tail. Furthermore, the kinetics of binding follows a log-normal distribution near the mean and a power law distribution at the tail. Our study provides new insights into the statistical nature of thermodynamics, kinetics and function from different ligands binding with a specific receptor or equivalently specific ligand binding with different receptors. The elucidation of distributions of the kinetics and free energy has guiding roles in studying biomolecular recognition and function through small-molecule evolution and chemical genetics
Single glass nanopore-based regenerable sensing platforms with a non-immobilized polyglutamic acid probe for selective detection of cupric ions
No full textA single glass capillary nanopore-based sensing platform for rapid and selective detection of cupric ions is demonstrated by utilizing polyglutamic acid (PGA) as a non-immobilized probe. The detection is based on the significant decrease of ionic current through nanopore and the reversal of ion current rectification responses induced by the chelated cupric ions on the probes when in the presence of cupric ions. PGA shows high selectivity for detecting cupric ions rather than other metal ions. The sensitivity of the sensing platform can be improved about 1-2 orders of magnitude by employing asymmetric salt gradients during the measurements. And the PGA-based nanopore sensing platform shows excellent regenerability for Cu2+ sensing applications. In addition, the method is found effective and reliable for the detection of cupric ions in real samples with small volume down to 20 mL. This nanopore-based sensing platform will find promising practical applications for the detection of cupric ions. (C) 2015 Elsevier B.V. All rights reserved
A facile method to prepare Pt/C/TiO2 nanotubes electrode for electro-oxidation of methanol
No full textIn this study, we prepared a Pt/C/TiO2 nanotubes (TiO2NTs) electrode by the facile pyrolysis of chloroplatinic acid and glucose on the TiO2NTs support simultaneously. By several characterization methods such as scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, it was found that with the thermal decomposition of H2PtCl6 and glucose simultaneously, Pt nanoparticles appeared with small particle size and anchored on the surface of TiO2NTs with carbon. Cyclic voltammetry and chronoamperometry were used to evaluate the electrocatalytic activity and stability of the prepared electrodes toward the oxidation of methanol. The Pt/C/TiO2NTs electrode possesses a large electrochemically active surface area and exhibits enhanced electrocatalytic activity and better stability for methanol oxidation than the Pt/TiO2NTs electrode. The Pt/C/TiO2NTs electrode provides a new approach for improving the catalytic activity and stability of Pt nanomaterials in renewable energy applications. (C) 2015 Elsevier Ltd. All rights reserved