Institute of Chemistry
Changchun Institute of Applied Chemistry, Chinese Academy Of SciencesNot a member yet
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Optimization of Broad-Response and High-Detectivity Polymer Photodetectors by Bandgap Engineering of Weak Donor-Strong Acceptor Polymers
No full textA series of weak donor-strong acceptor polymers containing two different electron-deficient units (diketopyrrolopyrrole and thienoisoindigo) are synthesized and used in broad-response and high-detectivity polymer photodetectors. By adjusting the composition ratio of the two acceptors, the absorption spectra, energy levels, molecular stacking, and film morphology are affected, which in turn influence the photodetector performance. With increased thienoisoindigo component, the HOMO energy levels shift from -5.41 to -4.76 eV, and the LUMO energy levels are nearly unchanged, corresponding to reduced bandgaps and red-shifted absorption spectra. 1,8-Diiodooctane additive shows greatly impact on the film morphology, which affects the photodetector performance significantly. Going from P1 to P5, the detectivity decreases, but the response range increases. The photodetector based on P4 exhibits detectivity of greater than 10(11) Jones in a broad spectral region of 300-1200 nm, which is really promising for UV-vis-NIR light detection
Guanidinated Thiourea-Decorated Polyethylenimines for Enhanced Membrane Penetration and Efficient siRNA Delivery
No full textRNA interference (RNAi) provides the promising treatments of gene-related diseases while hindered by the lack of highly efficient delivery platform with low cytotoxicity. Moreover, the intracellular fates of nonviral gene carriers are closely related to their internalization pathway, and eventually influence their RNAi efficiency. Herein, a series of guanidinated thiourea-modified polyethylenimines (PEI-MTU-Gs) are synthesized and utilized as the efficient carriers of small interfering RNA (siRNA) with up to 71.6% inhibition of luciferase activity in the luciferase-expressing cell lines (i.e., HeLa/Luc cells). The introduction of noncationic hydrogen bond donors, that is, thiourea groups, provides the carriers with much lower cytotoxicities and relatively looser complex structures that facilitate the intracellular release of siRNAs. Furthermore, the multiguanidino structures endow the PEI-MTU-G/siRNA complexes with the ability to directly penetrate cell membrane, which facilitates the cellular internalization while avoiding them suffering from the rigorous lysosomes. The results demonstrate PEI-MTU35-Gs as promising siRNA carriers for further gene therapy
Stabilized, Superparamagnetic Functionalized Graphene/Fe3O4@Au Nanocomposites for a Magnetically-Controlled Solid-State Electrochemiluminescence Biosensing Application
No full textHerein, a multifunctional nanoarchitecture has been developed by integrating the branched poly(ethylenimine) functionalized graphene/iron oxide hybrids (BGNs/Fe3O4) and luminol capped gold nanoparticles (luminol-AuNPs). The luminescent luminol-AuNPs as an electrochemiluminescence marker can be assembled on the nanocarrier of BGNs/Fe3O4 hybrids efficiently via the Au-N chemical bonds and electrostatic adsorption. Meanwhile, the multifunctional nanoarchitecture has been proved with excellent electron transfer, good stability, high emission intensity, etc. Furthermore, we successfully developed an ultrasensitive magnetically-controlled solid-state electrochemiluminescence (ECL) platform for label-free determination of HeLa cells using this multifunctional nanocomposite. Excellent performance of the magnetically-controlled ECL biosensing platform has been achieved including a high sensitivity for HeLa cells with a linear range from 20 to 1 x 10 (4) cells/mL, good stability, and reproducibility
Smart Plasmonic Glucose Nanosensors as Generic Theranostic Agents for Targeting-Free Cancer Cell Screening and Killing
No full textFast and accurate identification of cancer cells from healthy normal cells in a simple, generic way is very crucial for early cancer detection and treatment. Although functional nanoparticles, like fluorescent quantum dots and plasmonic Au nanoparticles (NPs), have been successfully applied for cancer cell imaging and photothermal therapy, they suffer from the main drawback of needing time-consuming targeting preparation for specific cancer cell detection and selective ablation. The lack of a generic and effective method therefore limits their potential high-throughput cancer cell preliminary screening and theranostic applications. We report herein a generic in vitro method for fast, targeting-free (avoiding lime-consuming preparations of targeting moiety for specific cancer cells) visual screening and selective killing of cancer cells from normal cells, by using glucose-responsive/-sensitive glucose oxidase-modified Ag/Au nanoshells (Ag/Au-GOx NSs) as a smart plasmonic theranostic agent. The method is generic to some extent since it is based on the distinct localized surface plasmon resonance (LSPR) responses (and colors) of the smart nanoprobe with cancer cells (typically have a higher glucose uptake level) and normal cells
Revealing the cellular localization of STAT1 during the cell cycle by super-resolution imaging
No full textSignal transducers and activators of transcription (STATs) can transduce cytokine signals and regulate gene expression. The cellular localization and nuclear trafficking of STAT1, a representative of the STAT family with multiple transcriptional functions, is tightly related with transcription process, which usually happens in the interphase of the cell cycle. However, these priority questions regarding STAT1 distribution and localization at the different cell-cycle stages remain unclear. By using direct stochastic optical reconstruction microscopy (dSTORM), we found that the nuclear expression level of STAT1 increased gradually as the cell cycle carried out, especially after EGF stimulation. Furthermore, STAT1 formed clusters in the whole cell during the cell cycle, with the size and the number of clusters also increasing significantly from G1 to G2 phase, suggesting that transcription and other cell-cycle related activities can promote STAT1 to form more and larger clusters for fast response to signals. Our work reveals that the cellular localization and clustering distribution of STAT1 are associated with the cell cycle, and further provides an insight into the mechanism of cell-cycle regulated STAT1 signal transduction
Intramolecular charge-transfer emission from conjugated polymer nanoparticles: the terminal group effect on electronic and optical properties
No full textTuning fluorescence properties and frontier orbital energy levels of hyperbranched conjugated polymer nanoparticles (HCPN-NMe) by the facile introduction of terminal N,N-dimethylaniline groups via an intramolecular charge transfer (ICT) process between the nanoparticle core and the terminal groups was demonstrated for the first time. Compared with the similar hyperbranched conjugated polymer nanoparticles with terminal benzene groups (HCPN-H), a large Stokes shift and remarkable fluorescence solvatochromism were observed for HCPN-NMe. Based on the environmental-sensitive ICT emission, HCPN-NMe can be used as a fluorescence sensor for the detection of water in THF with enhanced sensitivity
Controllable synthesis of a narrow polydispersity CO2-based oligo(carbonate-ether) tetraol
No full textA CO2-based oligo(carbonate-ether) tetraol was synthesized in a controlled manner by immortal copolymerization of carbon dioxide (CO2) and propylene oxide (PO) in the presence of 1,2,4,5-benzenetetracarboxylic acid (btcH(4)) catalyzed by using a zinc-cobalt double metal cyanide (Zn-Co-DMC) catalyst. The number average molecular weight (M-n) of the tetraol was in a good linear relationship with the molar ratio of PO and btcH4 (PO/btcH(4)), and hence can be precisely controlled. Besides, the rapid chain transfer in immortal copolymerization afforded the tetraol with a narrow polydispersity index (PDI) of 1.08 at a Mn of 1400 g mol(-1). Notably, the weight fraction of the byproduct propylene carbonate (W-PC) was reduced to as low as 4.0 wt%, which is the lowest W-pc ever reported for the synthesis of branched polyols. The structure of the oligo(carbonate-ether) tetraol was confirmed, providing new evidence for the effect of the acidity (pK(a1) value) of the chain transfer agent (CTA) on the initial catalytic mechanism. The acid only acts as the CTA directly participating in the copolymerization via the chain transfer reaction when its pK(a1) value is higher than that of adipic acid (pK(a1) = 4.43). However, when its pK(a1) value is lower than that of succinic acid (pK(a1) = 4.2), it acts as the initiate-transfer agent, which first initiates PO homopolymerization to an oligo-ether polyol, and then the in situ formed polyol acts as a new CTA for the copolymerization
High-quality hydrogen generated from formic acid triggered by in situ prepared Pd/C catalyst for fuel cells
No full textHigh-quality hydrogen can be generated from formic acid triggered by facilely in situ prepared Pd/C catalyst in ambient conditions. The obtained gas can be directly fed into proton exchange membrane fuel cells indicating a very promising application
Preparation of biocompatible, biodegradable and sustainable polylactides catalyzed by aluminum complexes bearing unsymmetrical dinaphthalene-imine derivatives via ring-opening polymerization of lactides
No full textA number of half-salen aluminum complexes bearing unsymmetrical [ONN]-type ligands were prepared from tridentate dinaphthalene-imine derivatives. These complexes were characterized by H-1 and C-13 NMR spectroscopy, elemental analysis and single crystal X-ray diffraction analysis. These complexes were employed for rac-lactide and L-lactide polymerization. Upon activation with isopropanol, complex (S)-B-6 (R-1 = R-2 = R-4 = H; R-3 = F) showed the highest activity (a monomer conversion of 94.6%) amid these aluminum complexes for the ring-opening polymerization of L-lactide; and complex (S)-B-2 (R-1 = R-2 = R-3 = H; R-4 = Bu-t) showed the highest stereoselectivity for the ring-opening polymerization of rac-lactide, obtaining a polylactide (PLA) with a Pm of 0.69. The polymerization kinetics utilizing (S)-B-6 as a catalyst were researched in detail. The data on the polymerization kinetics revealed that the rate of polymerization was first-order with respect to the monomer and the catalyst. There was a linear relationship between the L-lactide conversion and the number-average molecular weight of PLA
几种稀土微/纳米发光材料的可控合成及其性能研究
No full text微/纳米材料的形貌、尺寸和维度对其物理化学性质有着十分重要的影响，因此制备形貌可控的微/纳米材料、研究晶体的生长机理并探索其应用成为目前化学和材料学领域研究的热点。由于稀土元素独特的4f电子层结构，其化合物在光学、电学、磁学等各个领域都有广泛的应用。基于以上考虑，本文主要利用水热/溶剂热法制备了一系列稀土微/纳米材料，并对其生长机理、光谱特性和载药功能进行了研究。 通过掺杂Ca2+和Sr2+离子制备了常温稳定的六方相GdF3，碱土金属掺杂后引起的晶格膨胀和阴离子缺陷是六方相稳定的主要原因，以Eu3+离子为结构探针研究了正交相向六方相的转变过程。Ba2+离子虽不能引起相转变，但可作为形貌控制剂诱导正交相GdF3从亚微米盘演化为椭球状纳米结构。 在柠檬酸三钠的辅助下合成了磁性-荧光-多孔三功能BaGdF5纳米球。探讨了未掺杂激活离子时样品的发光机理，评价了样品的水溶性、细胞毒性和顺磁性能，并测...The chemical and physical properties of nano-/micromaterials are fundamentally related to their size, shape, and dimensionality, and therefore fabricating morphology-controlled nano-/micromaterials, understanding the crystal growth mechanism, and exploring their application has been the research hotspot in chemistry and material science. Rare earth compounds have been widely used in the fields of optics, electrics, and magnetism due to the unique characteristics resulting from the 4f electrons of rare earth ions. On the basis of above considerations, the dissertation is focused on the controllable synthesis of rare earth nano/micromaterials with hydro/solvthermal method. The growth mechanism, luminescent properties, and drug application in drug delivery have also been investigated. The mai..