RSC Advances
·
2016
·Vol. 6
·期 10
·7765-7771
·
IF 3.289
Ruipeng Hou,Xiaoqing Niu,Fengling Cui
A highly sensitive and selective label-free biosensor was designed for DNA determination based on target-induced opening of the hairpin DNA and forming a G-quadruplex with protoporphyrin IX (PPIX) as a signal reporter. In the absence of target-DNA (T-DNA), the probe-DNA (P-DNA) forms a hairpin structure. A G-rich sequence in the strand is partially caged in the stem-loop structure and cannot fold into a G-quadruplex. In the presence of T-DNA, the specific combination of targets with the sensing sequence (loop sequence) triggers the release of the G-rich sequence and allows it to fold properly and bind with PPIX resulting in the fluorescence of the G-quadruplex–PPIX providing the readout signal for the sensing event (detection limit of 3.5 nM). Based on the higher efficiency of Pb2+ at stabilizing G-quadruplexes than K+ and the Pb2+-stabilized G-quadruplexes not binding to PPIX, which resulted in fluorescence decrease, the proposed DNA-sensing system can be further exploited as a Pb2+-sensing method. The detection limit for Pb2+ is 2.6 nM.
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RSC Advances
·
2016
·Vol. 6
·期 91
·88234-88238
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IF 3.289
Z. Z. Zheng,J. Hu
Based on the different affinities of graphene oxide (GO) toward ssDNA and dsDNA, a fluorescence assay using split G-rich probes and magnetic GO (Fe3O4/GO) was developed for authentication of Pseudostellaria heterophylla based on the ITS sequences. In this assay, the probes mixed with Fe3O4/GO nanoparticles, hybridize with T-DNA for a double-stranded structure and then their G-rich sequences can fold into a G-quadruplex which combines hemin for DNAzyme. After magnetic separation, the DNAzyme supernatant can catalyze 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) oxidation with H2O2 and release a fluorescence signal. Herein, the Fe3O4/GO nanoparticles play an important role in decreasing the background signal by absorbing the excess probes and hemin. This assay allows the analysis of T-DNA in the range of 1.0 × 10−14 to 1.0 × 10−7 mol L−1 with a low detection limit of 1.87 × 10−15 mol L−1. In addition, this newly designed assay allows specific authentication of Pseudostellaria heterophylla from different provenances.
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ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Yafei Zhao,Ruoyan Wei,Xin Feng,Lining Sun,Panpan Liu,Yongxiang Su,Liyi Shi
Ultrathin graphite-like carbon nitride (g–C3N4) nanosheets have attracted considerable attention due to the enhanced intrinsic photoabsorption and photoresponse with respect to bulk g–C3N4. For the first time, a dual-mode of down- and upconversion luminescent g–C3N4 nanopaper with high optical transparency and mechanical robustness was successfully fabricated through a simple thermal evaporation process using chitosan as a green cross-linking agent. The dual-mode of down- and upconversion fluorescence emission originated from the amino terminated ultrathin g–C3N4 nanosheets functionalized with carboxylic acid modified multicolored rare-earth upconversion nanoparticles (cit–UCNPs) via EDC/NHS coupling chemistry. The homogeneously distributed cit–UCNPs@g–C3N4 nanoconjugates with excellent hydrophilicity displayed good film-forming ability and structural integrity; thus, the photoluminescence of each ingredient was substantially maintained. Results indicated that the freestanding chitosan cross-linked cit–UCNPs@g–C3N4 luminescent nanopaper possessed high transmittance, excellent mechanical properties, and remarkable dual-mode emission. The smart design of high performance luminescent nanopaper based on ultrathin g–C3N4 nanosheets grafted with multicolored UCNPs offers a potential strategy to immobilize other multifunctional luminescent materials for easily recognizable and hardly replicable anticounterfeiting fields.
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高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2016
·
IF 2.653
Li-Na Wen,Meng-Xia Xie
KRAS promoter can form G-quadruplex structure and regulate gene transcription. The drugs which can bind with G-quadruplex of KRAS promoter may be potential remedy for treatment of cancers associated with KRAS mutation. The interaction mechanism between the G-quadruplex of KRAS promoter and three isoquinoline alkaloids (jatrorrhizine, berberine and sanguinarine) has been investigated by UV-visible, fluorescence and circular dichroism spectroscopic methods. The results showed that the three alkaloids can form complexes with G-quadruplex KRAS promoter with the molecular ratio of 1:1, and the binding constants were (0.90 ± 0.16) × 10 6 L mol − 1 , (0.93 ± 0.21) × 10 6 L mol − 1 and (1.16 ± 0.45) × 10 6 L mol − 1 for jatrorrhizine , berberine and sanguinarine . The absorption spectra, KI quenching and fluorescence anisotropy and polarization studies suggested jatrorrhizine and berberine interacted with G-quadruplex by not only end-stacking binding mode but also grooves or loops binding mode, while sanguinarine by end-stacking binding mode. Sanguinarine was more beneficial to maintain the stability and parallel conformation of KRAS promoter G-quadruplex. MTT assay was performed to evaluate antiproliferation effects of the three isoquinoline alkaloids on SW620 cells, and the antiproliferation effects of the three alkaloids were sanguinarine > berberine > jatrorrhizine. All the three alkaloids can bind with KRAS promoter G-quadruplex, and sanguinarine had the better binding property and antiproliferation effects on SW620 cells. The results obtained are meaningful to explore potential reagents targeting the parallel G-quadruplex structure of KRAS promoter for gene theraphy of colorectal carcinomas.
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JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
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2017
·
IF 2.625
Qin Chen,Huijie Hou,Danwei Zhang,Shaogang Hu,Tao Min,Bingchuan Liu,Changzhu Yang,Wenhong Pu,Jingping Hu,Jiakuan Yang
The ZnO/g-C 3 N 4 photocatalyst was prepared by ball milling and demonstrated enhanced photocatalytic degradation of RhB under visible light irradiation. The photocatalyst is consisted of ZnO and g-C 3 N 4 heterojunctions formed by the shear stress during the mechanical treatment. The addition of g-C 3 N 4 can improve the photocatalytic performance of ZnO under visible light. The heterojunction formed between ZnO and g-C 3 N 4 decreased the recombination rate of photogenerated carriers and improved the photocatalytic activity of the ZnO/g-C 3 N 4 hybrids. The optimal ZnO/g-C 3 N 4 photocatalyst with 10 wt% g-C 3 N 4 showed a degradation efficiency of 51.3% for RhB under visible light, which is 2.1 times higher than that of pristine ZnO. The electron paramagnetic resonance (EPR) measurement showed that the OH radicals are the dominant active species in photocatalytic process under both full solar spectrum and visible light irradiation. And the OH radical generation is much more efficient under full solar spectrum than that under visible light due to the UV response of ZnO. This work provides a simple method for the design and preparation of novel heterojunction photocatalysts.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Chong Sun,Muhan Zhang,Qiqi Fei,Daoying Wang,Zhilan Sun,Zhiming Geng,Weimin Xu,Fang Liu
In this paper, a novel immunosensor was built for quantitative detection of heat shock protein 90 (HSP90) based on graphite-like carbon nitride nanosheets (g-C 3 N 4 NSs) hybridized with gold-F127 nanoparticles (g-C 3 N 4 -F127-Au NSs) modified electrode. The transmission electron microscope (TEM) was used to observe the structure and morphology of g-C 3 N 4 -F127-Au NSs. The successful preparation of g-C 3 N 4 -F127-Au NSs was characterized by UV–vis spectra, fourier transform infrared spectra (FTIR) and Raman spectra. Meanwhile, the electrochemical properties were measured by linear sweep voltammetric (LSV) and differential pulse voltammetry (DPV). Under the optimized conditions, the peak currents were linear with the concentration of HSP90 ranging from 3.5 μg/mL to 2.43 mg/mL. The linear regression equation was I (μA) = 10.31–10.05logc (R 2 = 0.9986, n = 9) with the detection limit of 2.67 μg/mL. Finally, the immunosensor exhibited good selectivity performance and provided a new approach for meat quality evaluation.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2016
·
IF 3.205
Yuanzhi Hong,Zhenyuan Fang,Bingxin Yin,Bifu Luo,Yong Zhao,Weidong Shi,Changsheng Li
The photocatalytic water splitting for generation of clean hydrogen energy has received increasingly attention in the field of photocatalysis . In this study, the Ta 2 O 5 /g-C 3 N 4 heterojunctions were successfully fabricated via a simple one-step heating strategy. The photocatalytic activity of as-prepared photocatalysts were evaluated by water splitting for hydrogen evolution under visible-light irradiation (λ > 420 nm). Compared to the pristine g-C 3 N 4 , the obtained heterojunctions exhibited remarkably improved hydrogen production performance. It was found that the 7.5%TO/CN heterojunction presented the best photocatalytic hydrogen evolution efficiency, which was about 4.2 times higher than that of pure g-C 3 N 4 . Moreover, the 7.5%TO/CN sample also displayed excellent photochemical stability even after 20 h photocatalytic test. By further experimental study, the enhanced photocatalytic activity is mainly attributed to the significantly improve the interfacial charge separation in the heterojunction between g-C 3 N 4 and Ta 2 O 5 . This work provides a facile approach to design g-C 3 N 4 -based photocatalyst and develops an efficient visible-light-driven heterojunction for application in solar energy conversion .
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SCIENCE OF THE TOTAL ENVIRONMENT
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2016
·
IF 3.976
Mei-Qiang Cai,Yi-Zu Zhu,Zong-Su Wei,Jian-Qiang Hu,Sheng-Dong Pan,Rui-Yang Xiao,Chun-Ying Dong,Mi-Cong Jin
Bimetallic oxide CuFeO 2 as a new heterogeneous catalyst has shown much higher catalytic ability for activating peroxide than single-metal oxides. The present work demonstrated a synergistic microwave (MW) enhanced Fenton-like process with CuFeO 2 for rapid decolorization of azo dye Orange G (OG). The MW irradiation dramatically enhanced the OG degradation efficiency, achieving 99.9% decolorization within 15 min at pH 5. The XRD analysis of reused CuFeO 2 , together with metal leaching tests, indicated merits of recycling for CuFeO 2 . The subsequent surface element analysis by XPS for fresh and used CuFeO 2 showed a complex network for reactions between copper-iron redox pairs and surface hydroxyl groups, leading to a synergistic Fenton-like system accelerated by MW irradiation. In the CuFeO 2 initiated Fenton-like reactions, several oxidant species (i.e., OH, O 2 − , electron hole , and Fe IV O) responsible to the OG oxidation were identified by quenching experiments, showing the MW generated high temperature and “hot spots” enhanced the yield of OH by generation of electron-hole pairs. Further, the 26 detected degradation products confirmed the OH dominant oxidation of OG. This study shows that the MW-enhanced Fenton-like reaction using CuFeO 2 has potential applications for rapid decolorization of dye effluent.
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ANALYTICAL CHEMISTRY
·
2016
·
IF 5.886
Haojun Jin,Yuqian Liu,Tianshu Xu,Xiaojun Qu,Feika Bian,Qingjiang Sun
By complexing a nonionic G-quadruplex ligand with hybrid dual-emission quantum dots (QDs), a ratiometric fluorescent nanoprobe is developed for G-quadruplex detection in a sensitive and specific manner. The QDs nanohybrid comprised of a green-emission QD (gQD) and multiple red-emission QDs (rQDs) inside and outside of a silica shell, respectively, is utilized as the signal displaying unit. Only the presence of G-quadruplex can displace the ligand from QDs, breaking up the QDs–ligand complexation, and inducing the restoration of the rQDs fluorescence. Since the fluorescence of embedded gQD stays constant, variations of the dual-emission intensity ratios display continuous color changes from green to bright orange, which can be clearly observed by the naked eye. Furthermore, by utilizing competitive binding of a cationic ligand versus the nonionic ligand toward G-quadruplex, the nanoprobe is demonstrated to be applicable for assessing the affinity of a G-quadruplex-targeted anticancer drug candidate, exhibiting ratiometric fluorescence signals (reverse of that for G-quadruplex detection). By making use of the specificity of the ligand binding with G-quadruplex against a double helix, this nanoprobe is also demonstrated to be capable of sensitive detection of one-base mutation, exhibiting sequence-specific ratiometric fluorescence signals. By functionalizing with a nuclear localization peptide, the nanoprobe can be used for visualization of G-quadruplex in the nucleus of human cells.
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CHINESE JOURNAL OF POLYMER SCIENCE
·
2013
·Vol. 31
·期 4
·691-701
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IF 1.27
Tan Lin,Xing Jin-xing,Cao Fu-hu,Chen Li-juan,Zhang Chong,Shi Rong-hua,Wang Yan-mei
A series of double-hydrophilic double-grafted PMA- g -PEG/PDMA copolymers, which contained poly(methacrylate) (PMA) as backbone, poly(ethylene glycol) (PEG) and poly( N,N -dimethylacrylamide) (PDMA) as side chains synthesized successfully by using reversible addition-fragmentation chain transfer (RAFT) polymerization and atom transfer radical polymerization (ATRP), were used as physical coatings for the evaluation of protein-resistant properties by capillary electrophoresis (CE). Electroosmotic flow (EOF) measurement results showed that the PMA- g -PEG/PDMA copolymer coated capillaries could suppress electroosmotic mobility in a wide pH range (pH = 2.8–9.8) and EOF mobility decreased with the increase of copolymer molecular mass and PDMA content. At the same time, protein recovery, theoretical plate number of separation and repeatability of migration time demonstrated that antifouling efficiency was improved with the increase of molecular mass and PEG content.
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RSC Advances
·
2015
·Vol. 5
·期 120
·99418-99424
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IF 3.84
Jinda Fang,Ke Zhang,Jingwei Jia,Zhengke Wang,Qiaoling Hu
To improve the drug-loading capacity and control the initial release of amphiphilic drug carriers, a series of N-phthaloyl-chitosan-g-(PEO–PLA–PEO) compounds were synthesized with well-defined structures. The self-assembly behavior of copolymers in aqueous solutions was confirmed by various techniques such as fluorescence spectrometry, dynamic light scattering, and transmission electron microscopy. The results demonstrated that the micellization behavior of graft copolymers was different from that of their linear counterparts. The micelle sizes of the graft copolymers could be tuned with chemical composition as well as temperature. Furthermore, when hydrophobic indomethacin was loaded into the micelles, the graft copolymer micelles trapped more indomethacin than PEO–PLA–PEO micelles, facilitating the in vitro control of the initial burst release of the drug. Drug release could be controlled in vitro by simply altering the EO/LA ratio of the grafting chains. The graft copolymer showed low cytotoxicity to 293T cells, indicating its great potential application for drug delivery.
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Journal of Physical Chemistry C
·
2015
·
IF 4.772
Yuangang Li,Rongrong Wang,Huajing Li,Xiaoliang Wei,Juan Feng,Kaiqiang Liu,Yongqiang Dang,Anning Zhou
Co-Pi decorated TiO2@graphitic carbon nitrides (g-C3N4) nanorod arrays (denoted as CCNRs) with different mass ratios of g-C3N4 have been constructed on the FTO substrate through three processes, hydrothermal growth, chemical bath deposition and electrodeposition. First, TiO2 nanorod arrays were grown onto a FTO substrate by a hydrothermal method. Second, g-C3N4 was coated onto the TiO2 nanorod arrays by immersing the above substrate with TiO2 nanorod arrays into a solution of urea and then heated at higher temperature. In this procedure, the amount of the g-C3N4 on the TiO2 nanorod arrays can be controlled by tuning the concentration of the urea solution. At last, Co-Pi were decorated on the surface of the TiO2@g-C3N4 by electrodeposition. The as-prepared CCNRs were characterized by XRD, FESEM, TEM, XPS, UV–vis, and FTIR, respectively, which illustrated that Co-Pi moieties were successfully decorated on the hybrid TiO2@g-C3N4 nanorod arrays. Photoelectrochemical (PEC) measurements have demonstrated that the prepared CCNRs serve as an efficient and stable photoanode for PEC seawater splitting. The photocurrent density reaches 1.6 mA/cm2 under 100 mW/cm2 (AM1.5G) light illumination at 1.23 V (RHE). More significantly, the CCNRs photoanode is quite stable during seawater splitting and the performance remain undiminished even after 10 h continuous illumination. Finally, a systematical photocatalytic mechanism of the Co-Pi decorated TiO2@g-C3N4 was proposed, and it can be considered as potential explanation of enhanced PEC performance.
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