Institute of Chemistry
Changchun Institute of Applied Chemistry, Chinese Academy Of SciencesNot a member yet
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Low bandgap conjugated polymers based on mono-fluorinated isoindigo for efficient bulk heterojunction polymer solar cells processed with non-chlorinated solvents
No full textThree low bandgap conjugated polymers based on 7-fluorinated isoindigo (IID1F) and dithieno[3,2-b;6,7-b]carbazole (DTC), i.e., poly[N-dodecyldithieno[3,2-b;6,7-b]carbazole-alt-7-fluoro-N,N-di(2-octyldodecyl)isoindigo] (P1), poly[N-dodecyldithieno[3,2-b;6,7-b] carbazole-alt-7-fluoro-N,N-di(3-octyltridecyl)isoindigo] (P2) and poly[N-dodecyldithieno[3,2-b;6,7-b] carbazole-alt-7-fluoro-N,N-di(4-octyltetradecyl)isoindigo] (P3), were synthesized. All three polymers are soluble in non-chlorinated solvent o-xylene owing to regio-random distribution of F-atoms along the conjugated backbone. The position of the alkyl-branching point has a negligible influence on energy levels and absorption spectra of the polymers, but has a small effect on their charge transport properties. Bulk heterojunction (BHJ) polymer solar cells (PSCs) of the polymers were fabricated with phenyl-C-61-butyric acid methyl ester (PC61BM) as an electron acceptor. When o-xylene was used as a solvent, all three polymers delivered power conversion efficiencies (PCEs) above 7%. P2 exhibited the best device performance with a PCE of 7.5%. The devices processed with o-xylene showed higher device efficiency than those fabricated with o-dichlorobenzene (o-DCB) since the films of polymer: PC61BM blends prepared with o-xylene exhibited better morphology and higher and more balanced charge-carrier mobilities, leading to less recombination loss and higher fill factor (FF)
Using Plasmonic Copper Sulfide Nanocrystals as Smart Light-Driven Sterilants
No full textAs an efficient route to control pet overpopulation and develop neutered experimental animals, male sterilization via surgical techniques, chemical injections, and antifertility vaccines has brought particular attention recently. However, these traditional ways usually induce long-term adverse reactions, immune suppression, and serious infection and pain. To overcome the above limitations, we developed a platform in the present study by using plasmonic copper sulfide nanocrystals (Cu2-xS NCs) as intelligent light-driven sterilants with ideal outcomes. Upon NIR laser irradiation, these well-prepared Cu2-xS NCs can possess NIR-induced hyperthermia and generate high levels of reactive oxygen species (ROS). Due to the cooperation of photothermal and photodynamic effects, these nanocrystals exhibited NIR-mediated toxicity toward Sertoli cells both in vitro and in vivo in a mild manner. We attribute the potential mechanism of cellular injury to the apoptosis-related death and denaturation of protein in the testicles. Furthermore, the possible metabolism route and long-term toxicity of these nanocrystals after testicular injection indicate their high biocompatibility. Taking together, our study on the NIR-induced toxicity of Cu2-xS NCs provides keen insights for the usage of plasmonic nanomaterials in biomedicine
Improved Thermal Stability of Polymer Solar Cells by Incorporating Porphyrins
No full textThermal stability has been the important issue in organic solar cell, especially for the large scale fabrication and application in the future. In this work, a new strategy involving the introduction of porphyrin compound (BL) is proposed to prevent the [6,6]-phenyl C61 butyric acid methyl ester (PC61BM) aggregation. The supramolecular interactions between PC61BM and BL are first demonstrated in PC61BM:BL binary blend, and then the effect of BL on P3HT:PC61BM blend is qualitatively and quantitatively studied by differential scanning calorimetry, UV-vis absorption spectroscopy, atomic force microscopy, optical microscopy, and fluorescence techniques. It is found that the BL addition not only stabilizes the morphology of P3HT:PC61BM blend films, but also shows a good ability to maintain the electron mobility by depressing the PC61BM crystallization. And the thermal stability of the devices based on P3HT:PC61BM:BL ternary blend films is therefore greatly improved. For example, 8 wt% BL doping drops the power conversion efficiency by 10.5% relative to its peak value after 48 h of annealing at 130 degrees C, while 71.5% of decrease is obtained for the device without BL after only 3 h of annealing. This strategy is preliminarily proved to be universal and will show great potentials in future commercialization of polymer solar cells
Tumor Microenvironment Activated Photothermal Strategy for Precisely Controlled Ablation of Solid Tumors upon NIR Irradiation
No full textPhotothermal ablation has provided emerging and promising opportunities to further potentiate the efficacy of postoperative chemotherapy of tumor. However, it still cannot achieve a high level of selectivity because extraneous photodamage along the optical path to the tumor is unavoidable as the result of the uncontrollable distribution of the photothermal agents. In addition, it is technically difficult to keep photoirradiation localizing only on cancer cells. In this report, a new strategy is introduced for precisely controlled ablation of tumor through tumor microenvironment activated near-infrared (NIR) photothermal therapy. By taking advantage of the pH-dependent light-heat conversion property of Au@PANI nanoparticles, much higher photothermal effect at pH 6.5 than that at pH 7.4 is achieved. Therefore, in normal tissues and blood vessels, NIR irradiation cannot lead to a lethal temperature with little or no harm to normal cells. In contrast, in acidic tumor microenvironment, the photothermal effect is activated. Consequently, NIR irradiation can effectively kill cancer cells through local hyperthermia. Importantly, with the benefit of the internal and external control to switch on the photothermal ablation, the technical difficulty to precisely localize laser irradiation on tumor cells can be circumvented
Deciphering a Nanocarbon-Based Artificial Peroxidase: Chemical Identification of the Catalytically Active and Substrate-Binding Sites on Graphene Quantum Dots
No full textThe design and construction of efficient artificial enzymes is highly desirable. Recent studies have demonstrated that a series of carbon nanomaterials possess intrinsic peroxidase activity. Among them, graphene quantum dots (GQDs) have a high enzymatic activity. However, the catalytic mechanism remains unclear. Therefore, in this report, we chose to decipher their peroxidase activity. By selectively deactivating the ketonic carbonyl, carboxylic, or hydroxy groups and investigating the catalytic activities of these GQD derivatives, we obtained evidence that the -C=O groups were the catalytically active sites, whereas the O=C-O- groups acted as substrate-binding sites, and -C-OH groups can inhibit the activity. These results were corroborated by theoretical studies. This work should not only enhance our understanding of nanocarbon-based artificial enzymes, but also facilitate the design and construction of other types of target-specific artificial enzymes
DNA-based advanced logic circuits for nonarithmetic information processing
No full textDNA has been used as a building block to construct a series of complex logic circuits to perform nonarithmetic functions, including a multiplexer, demultiplexer, encoder and decoder. This is the first time that DNA has been used to cover this broad range of logic circuits, demonstrating the versatility and power of DNA computation to process information on the molecular level. The above logic circuits all share the same DNA platform, indicating the great prospects for DNA computation. The enzyme-free system developed here provides a novel prototype for the design of DNA-based, high-level molecular logic circuits. Considering its biocompatibility, DNA computation could find potential applications in biological and biomedical fields in the not-too-distant future
Surface Oxidized Cobalt-Phosphide Nanorods As an Advanced Oxygen Evolution Catalyst in Alkaline Solution
No full textElectrochemical water splitting in alkaline solution plays a growing role in alternative energy devices due to the need for clean and sustainable energy. However, catalysts that are active for both hydrogen evolution and oxygen evolution reactions are rare. Herein, we demonstrate that cobalt phosphide (CoP), which was synthesized via the hydrothermal route and has been shown to have hydrogen evolution activity, is highly active for oxygen evolution. A current density of 10 mA cm(-2) was generated at an overpotential of only 320 mV in 1 M KOH for a CoP nanorod-based electrode (CoP NR/C), which was competitive with commercial IrO2. The Tafel slope for CoP NR/C was only 71 mV dec(-1), and the catalyst maintained high stability during a 12 h test. This high activity was attributed to the formation of a thin layer of ultrafine crystalline cobalt oxide on the CoP surface
New chemosynthetic route to linear epsilon-poly-lysine
No full textepsilon-Poly-lysine (epsilon-PL) is an uncommon cationic, naturally-occurring homopolymer produced by the fermentation process. Due to its significant antimicrobial activity and nontoxicity to humans, epsilon-PL is now industrially produced as an additive, e.g. for food and cosmetics. However, the biosynthetic route can only make polymers with a molecular weight of about 3 kDa. Here, we report a new chemical strategy based on ring-opening polymerization (ROP) to obtain epsilon-PL from lysine. The 2,5-dimethylpyrrole protected alpha-amino-epsilon-caprolactam monomer was prepared through cyclization of lysine followed by protection. ROP of this monomer, followed by the removal of the protecting group, 2,5-dimethylpyrrole, ultimately yielded epsilon-PL with varying molecular weights. The structure of this chemosynthetic epsilon-PL has been fully characterized by H-1 NMR, C-13 NMR, and MALDI-TOF MS analyses. This chemosynthetic epsilon-PL exhibited a similar pK(a) value and low cytotoxicity as the biosynthetic analogue. Using this new chemical strategy involving ROP without the need for phosgene may enable a more cost effective production of epsilon-PL on a larger-scale, facilitating the design of more advanced biomaterials
Pulmonary Codelivery of Doxorubicin and siRNA by pH-Sensitive Nanoparticles for Therapy of Metastatic Lung Cancer
No full textA pulmonary codelivery system that can simultaneously deliver doxorubicin (DOX) and Bcl2 siRNA to the lungs provides a promising local treatment strategy for lung cancers. In this study, DOX is conjugated onto polyethylenimine (PEI) by using cis-aconitic anhydride (CA, a pH-sensitive linker) to obtain PEI-CA-DOX conjugates. The PEI-CA-DOX/siRNA complex nanoparticles are formed spontaneously via electrostatic interaction between cationic PEI-CA-DOX and anionic siRNA. The drug release experiment shows that DOX releases faster at acidic pH than at pH 7.4. Moreover, PEI-CA-DOX/Bcl2 siRNA complex nanoparticles show higher cytotoxicity and apoptosis induction in B16F10 cells than those treated with either DOX or Bcl2 siRNA alone. When the codelivery systems are directly sprayed into the lungs of B16F10 melanoma-bearing mice, the PEI-CA-DOX/Bcl2 siRNA complex nanoparticles exhibit enhanced antitumor efficacy compared with the single delivery of DOX or Bcl2 siRNA. Compared with systemic delivery, most drug and siRNA show a long-term retention in the lungs via pulmonary delivery, and a considerable number of the drug and siRNA accumulate in tumor tissues of lungs, but rarely in normal lung tissues. The PEI-CA-DOX/Bcl2 siRNA complex nanoparticles are promising for the treatment of metastatic lung cancer by pulmonary delivery with low side effects on the normal tissues
