查找使用阿拉丁产品的科研文献

Trace thiabendazole in apple juice detection from β- cyclodextrin surface modified silver nanoparticles based surface enhanced Raman spectroscopy

Yan Wang,Tingting Hu,Xiaoyu Han,Jihong Zhang,Jun Xie,Jianjun Han

Rapid and highly sensitive detection thiabendazole (TBZ), as an effective broad-spectrum fungicide for preservation in fruits and vegetables, has become an urgent issue due to rising food safety requirements. In this research, beta-cyclodextrin (β-CD) directly reduced and modified silver nanoparticles (β-CD-Ag NPs) with uniform average ∼ 42.5 nm diameters were synthesized from AgNO 3 solution precursor. Surface-enhanced Raman spectroscopy (SERS) performance of β-CD-Ag NPs was evaluated using crystal violet as analyte molecule. The results indicate the lowest detection limit can reach 10 -12 M, with a 9.05 × 10 7 calculated enhancement factor. The improved SERS performance can be attributed to the capture of analyte molecules from special cavity structure of β-CD, and high local surface plasma resonance (LSPR) induced electric field intensities. The lowest detection limit of β-CD-Ag NPs for standard TBZ solution can reach 47 ppb, and the relationship between Raman intensities and TBZ concentrations show well linear, which indicates possible quantitative analysis. Furthermore, the detection also presents excellent reproducibility and stability. Lowest 66 ppb TBZ in apple juice can be detected from SERS of β-CD-Ag NPs, with 92% to 128% recoveries. The absorption and Fourier transform infrared transmittance spectra confirm that the molecules capture and chemical bonding formation between TBZ and β-CD are responsible for the trace detection. This research provides a possible method for the detection of pesticide residues in food and environmental systems.

Electrochemical biosensor for hydroxymethylated DNA detection and β-glucosyltransferase activity assay based on enzymatic catalysis triggering signal amplification

Huanshun Yin,Zhiqing Yang,Haiyan Wang,Yunlei Zhou,Shiyun Ai

A simple and sensitive electrochemical biosensor was fabricated for hydroxymethylated DNA detection and T4 β-glucosyltransferase activity assay based on the glycosylation of hydroxymethylated DNA and Hpa II restriction endonuclease system triggering signal amplification. After immobilizing double-stranded DNA (dsDNA) on the surface of carboxyl functionalized Fe 3 O 4 nanoparticle, the glycosylation reaction of hydroxymethylated cytosine can be performed with the catalytic effect of T4 β-glucosyltransferase using uridine diphosphoglucose as glucose donor. Then, 4-mercaptophenylboronic acid (4-MPBA) can be further reacted with glucose and captured on Fe 3 O 4 nanoparticle surface. After the dsDNA was digested by Hpa II, the fragment with 4-MPBA can be released from Fe 3 O 4 nanoparticle surface. After magnetic separation, this fragment can be further modified on gold electrode surface through the interaction between Au and −SH, which can result in a decreased electrochemical signal of [Fe(CN) 6 ] 3− . According to this detection strategy, the electrochemical biosensor showed high sensitivity with the low detection limits of 0.14   nM and 0.27 unit/mL for hydroxymethylated DNA and T4 β-glucosyltransferase. The fabricated biosensor also presented high selectivity and acceptable reproducibility. In addition, the inhibition activity of 4-phenylimidazole towards T4 β-glucosyltransferase was also investigated. This work provides a novel platform for hydroxymethylated DNA detection, T4 β-glucosyltransferase activity assay and its inhibition screening.

Voltammetric chiral discrimination of tryptophan using a multilayer nanocomposite with implemented amino-modified β-cyclodextrin as recognition element

Song Jinyi,Yang Chengcheng,Ma Jiao,Han Qian,Ran Peiyao,Fu Yingzi

An electrochemical chiral multilayer nanocomposite was prepared by modifying a glassy carbon electrode (GCE) via opposite-charge adsorption of amino-modified β-cyclodextrin (NH 2 -β-CD), gold-platinum core-shell microspheres (Au@Pts), polyethyleneimine (PEI), and multi-walled carbon nanotubes (MWCNTs). The modified GCE was applied to the enantioselective voltammetric determination of tryprophan (Trp). The Au@Pts enable an effective immobilization of the chiral selector (NH 2 -β-CD) and enhance the electrochemical performance. Scanning electron microscopy, transmission electron microscopy, UV-vis spectroscopy, FTIR and electrochemical methods were used to characterize the nanocomposite. Trp enantiomers were then determined by differential pulse voltammetry (DPV) (with a peak potential of +0.7 V vs. Ag/AgCl). The recognition efficiency was expressed by an increase in peak height by about 32% for DPV determinations of L-Trp compared to D-Trp in case of a 5 mM Trp solution of pH 7.0. Response was linear in the 10 μM to 5.0 mM concentration range, and the limits of detection were 4.3 μM and 5.6 μM with electrochemical sensitivity of 43.5 μA·μM −1 ·cm −2 and 34.6 μA·μM −1 ·cm −2 for L-Trp and D-Trp, respectively (at S/ N  = 3). Schematic of an electrochemical chiral multilayer nanocomposite composed of multi-walled carbon nanotubes (MWCNTs), polyethyleneimine (PEI), gold-platinum core-shell microspheres (Au@Pt) and amino-modified β-cyclodextrin (NH 2 -β-CD). It was prepared by modifying a glassy carbon electrode (GCE) for enantioselective voltammetric determination of tryptophan (Trp) enantiomers.

Synergistic Ag(I)/nBu4NBr-catalyzed fixation of CO2 to β-oxopropyl carbonates via propargylic alcohols and monohydric alcohols

Jingyuan Li,Qingwen Song,Hengxuan Zhang,Ping Liu,Kan Zhang,Junwen Wang,Dengsong Zhang

Chemical fixation of carbon dioxide under mild reaction conditions e.g. atmospheric pressure and low temperature depends upon the ability of catalyst. Herein, a synergistic catalytic scheme of silver sulfadiazine/ n Bu 4 NBr was described for the three-component reaction of propargylic alcohols, CO 2 , and monohydric alcohols. This catalytic system was demonstrated effectively to provide β-oxopropyl carbonates in excellent yields (up to 99% yield with 5 mol% catalyst). The method tolerated a wide scope of propargylic alcohols and monohydric alcohols under atmospheric CO 2 pressure and solvent-free conditions. The excellent catalytic performance was attributed to the synergistic catalysis confirmed by the careful experiments.

Preparation, Characterization, and In Vitro/In Vivo Evaluation of 3-O-β-D-Galactosylated Resveratrol-Loaded Polydopamine Nanoparticles

Wang Beilei,Shan Xiaoxiao,Lv Shujie,Zha Liqiong,Zhang Caiyun,Dong Qiannian,Chen Weidong

3-O-β-D-galactosylated resveratrol (Gal-Res) was synthesized from resveratrol (Res) and 3-O-β-D-galactose (Gal) in our previous study. In order to improve the pH sensitivity and bioavailability of Gal-Res, Gal-Res nanoparticles (Gal-Res NPs) were prepared using polydopamine (PDA) as a drug carrier. The drug loading (DL %) and entrapment efficiency (EE %) of Gal-Res NPs were 46.80% and 88.06%. The average particle size, polydispersity index (PDI), and Zeta potential of Gal-Res NPs were 179.38 ± 2.83 nm, 0.129 ± 0.013, and − 28.05 ± 0.36 mV, respectively. The transmission electron microscope (TEM) showed that Gal-Res NPs had uniform spherical morphology. Compared with the fast release of raw Gal-Res, the in vitro release of Gal-Res NPs was slow and pH-sensitive. The results of the blood vessel irritation and hemolysis test demonstrated that Gal-Res NPs had good hemocompatibility. The pharmacokinetics study in rats showed that area under the curve of plasma drug concentration time (AUC 0→600 ) and half-life (t 1/2 ) of Gal-Res NPs were enhanced 1.82-fold and 2.19-fold higher than those of raw Gal-Res. The in vivo biodistribution results showed that Gal-Res NPs were more distributed in liver tissue than Gal-Res. Gal-Res NPs with high bioavailability and liver accumulation were hopeful drug delivery systems (DDS) to treat liver diseases. Graphical abstract

USP43 impairs cisplatin sensitivity in epithelial ovarian cancer through HDAC2-dependent regulation of Wnt/β-catenin signaling pathway

Pei Lipeng,Zhao Feng,Zhang Yi

Epithelial ovarian cancer (EOC) is the leading cause of cancer death all over the world. USP43 functions as a tumor promoter in various malignant cancers. Nevertheless, the biological roles and mechanisms of USP43 in EOC remain unknown. In this study, USP43 was highly expressed in EOC tissues and cells, and high expression of USP43 were associated with a poor prognosis of EOC. USP43 overexpression promoted EOC cell proliferation, enhanced the ability of migration and invasion, decreased cisplatin sensitivity and inhibited apoptosis. Knockdown of USP43 in vitro effectively retarded above malignant progression of EOC. In vivo xenograft tumors, silencing USP43 slowed tumor growth and enhanced cisplatin sensitivity. Mechanistically, USP43 inhibited HDAC2 degradation and enhanced HDAC2 protein stability through its deubiquitylation function. USP43 diminished the sensitivity of EOC cells to cisplatin through activation of the Wnt/β-catenin signaling pathway mediated by HDAC2. Taken together, the data in this study revealed the functions of USP43 in proliferation, migration, invasion, chemoresistance of EOC cells, and the mechanism of HDAC2-mediated Wnt/β-catenin signaling pathway. Thus, USP43 might serve as a potential target for the control of ovarian cancer progression.

Superior TRAIL gene expression and cancer cell apoptosis mediated by highly branched-linear poly(β-amino ester)s

Zhao Yitong,Bo Tao,Wang Chenfei,Yao Dingjin,Pan Chaolan,Xu Weiyi,Zhou Hao,Li Ming,Zhang Si

Extensive efforts have been dedicated to enhancing the expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in cancer cells for the development of effective cancer treatments. However, highly safe and efficient delivery of TRAIL gene remains a significant challenge, especially using cationic polymers. Here, a series of highly branched-linear poly(β-amino ester)s (H-LPAEs) are developed through a unique oligomer branching strategy. H-LPAEs exhibit a more uniform distribution of linear segments and branching units, leading to excellent DNA condensation and favorable physicochemical properties of H-LPAE/DNA polyplexes. In SW1353 and BMSC cells, the optimized H-LPAEs, H-LPAE B4−S5−TMPTA , achieves superior gene transfection efficiency of 58.0% and 33.4%, which were 2.5-fold and 2.0-fold higher than that of the leading commercial gene transfection reagent, Lipofectamine 3000. Excitingly, H-LPAE B4−S5−TMPTA mediated 56.7% and 28.1% cell apoptosis in HepG2 cells and HeLa cells highlighting its potential application in cancer gene therapy. In addition, locally administered H-LPAE B4−S5−TMPTA delivered TRAIL DNA to HepG2 xenograft tumors and inhibited tumor growth in vivo. This study not only proposes a novel strategy for synthesizing poly(β-amino ester)s with a unique branched-linear topology but also identifies a promising candidate for highly efficient TRAIL gene transfection.

Ru nanoclusters confined on α/β cobalt hydroxide nanosheets as efficient bifunctional oxygen electrocatalysts for Zn–air batteries

Yu Zhang,Ting Hu,Changwang Ke,Fengyan Han,Weiping Xiao,Xiaofei Yang

Rational regulation of the coordination environment of Ru active sites by employing layered transition metal hydroxides as the substrate could achieve high catalytic performance towards the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR). However, it is still challenging to clarify the interactions between the Ru catalysts and the layered transition metal hydroxides in different phases and also to unveil the mechanism responsible for the boosted performance. Herein, we report novel Ru nanocluster-decorated few-layer Co(OH)2 nanosheets, which are employed as a model to investigate the structure–property relationship between zero-dimensional (0D) noble metal catalysts and two-dimensional (2D) substrates toward electrochemical reactions. The obtained α-Co(OH)2-Ru catalyst exhibits a very low potential difference (ΔE) of 0.557 V between the half-wave potential towards the ORR and the potential at 10 mA cm−2 towards the OER, which is smaller than those of β-Co(OH)2-Ru (0.614 V), α-Co(OH)2 (0.774 V) and β-Co(OH)2 (0.897 V). Density functional theory (DFT) calculations further reveal that the reaction energy barrier of the rate-determining step of α-Co(OH)2-Ru is much smaller than those of β-Co(OH)2-Ru and Ru, implying that the strong electronic interactions between Ru nanoclusters and layered α-Co(OH)2 nanosheets contribute majorly to the enhanced catalytic performance. Furthermore, the optimized α-Co(OH)2-Ru nanohybrid is employed as the air electrode to assemble rechargeable Zn–air batteries, which possesses a power density of 187.8 mW cm−2 and a long-term durability of 400 cycles without obvious attenuation.

Core–shell structured luminescent and mesoporous β-NaYF4:Ce3+/Tb3+@mSiO2-PEG nanospheres for anti-cancer drug delivery

Yuan Wu,Dongmei Yang,Xiaojiao Kang,Ping'an Ma,Shanshan Huang,Yang Zhang,Chunxia Li,Jun Lin

Multifunctional nanocomposites integrating mesoporous and luminescence properties into a single entity are synthesized via a facile and effective approach. Oleic acid capped β-NaYF4:Ce3+/Tb3+ nanoparticles (NPs) are transferred into aqueous solution by cetyltrimethylammonium bromide (CTAB) surfactants, and further encapsulated with uniform mesoporous silica shell followed by the surface modification with poly(ethylene glycol) (PEG), leading to the formation of water-dispersible and biocompatible core–shell structured β-NaYF4:Ce3+/Tb3+@mSiO2-PEG (denoted as NPs@mSiO2-PEG) nanospheres. The as-synthesized nanospheres show a typical mesoporous structure and a green emission under UV irradiation. Doxorubicin hydrochloride (DOX), a widely used anti-cancer drug, is used as a model drug to evaluate the loading and controlled release behaviors of the NPs@mSiO2-PEG in phosphoric acidic buffer solutions (PBS) at different pH values (pH = 7.4 and 5.0). The composite carriers provide a pH-sensitive drug release pattern and the drug releases faster under lower pH value. The endocytosis process of fluorescein isothiocyanate (FITC)-labelled nanospheres is characterized using flow cytometry and confocal laser scanning microscopy (CLSM) against A549 cells. The in vitro cytotoxic effect against A549 cells of the DOX-loaded carriers is investigated in detail. In addition, the extent of drug release can be monitored by the variation of photoluminescence (PL) intensity of β-NaYF4:Ce3+/Tb3+. Considering the good biocompatibility and pH-dependent drug release pattern, such core–shell structured luminescent NPs@mSiO2-PEG nanospheres have potential applications in controlled drug delivery.

Using Multifunctional Peptide Conjugated Au Nanorods for Monitoring β-amyloid Aggregation and Chemo-Photothermal Treatment of Alzheimer's Disease

Meng Li,Yijia Guan,Andong Zhao,Jinsong Ren,Xiaogang Qu

Development of sensitive detectors of Aβ aggregates and effective inhibitors of Aβ aggregation are of diagnostic importance and therapeutic implications for Alzheimer's disease (AD) treatment. Herein, a novel strategy has been presented by self-assembly of peptide conjugated Au nanorods (AuP) as multifunctional Aβ fibrillization detectors and inhibitors. Our design combines the unique high NIR absorption property of AuNRs with two known Aβ inhibitors, Aβ15-20 and polyoxometalates (POMs). The synthesized AuP can effectively inhibit Aβ aggregation and dissociate amyloid deposits with NIR irradiation both in buffer and in mice cerebrospinal fluid (CSF), and protect cells from Aβ-related toxicity upon NIR irradiation. In addition, with the shape and size-dependent optical properties, the nanorods can also act as effective diagnostic probes to sensitively detect the Aβ aggregates. This is the first report to integrate 3 segments, an Aβ-targeting element, a reporter and inhibitors, in one drug delivery system for AD treatment.

Intradermal injection of icariin-HP-β-cyclodextrin improved traumatic brain injury via the trigeminal epineurium-brain dura pathway

Wei Yang,Yong-Hui Han,Heng-Cai Wang,Cui-Tao Lu,Xi-Chong Yu,Ying-Zheng Zhao

Ferroelectric β-crystalline phase formation and property enhancement in polydopamine modified BaTiO3/poly (vinylidene fluoride-trifluoroethylene) nanocomposite films

Tingting Men,Xin Liu,Baohua Jiang,Xifa Long,Haiyan Guo

Piezopolymer poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) films doped with BaTiO 3 (BT) and polydopamine coated BT (BT-Pdop) nanoparticles were prepared by spin-coating method. Polydopamine modifies the interfaces of inorganic BT nanoparticles and PVDF-TrFE matrix with its polar hydroxyl groups, enhancing the piezoelectric β -phase. BT-Pdop nanoparticles were obtained in pH 8.5 buffer solution . For ferroelectric PVDF-TrFE, the favorable piezoelectric property comes from its ferroelectricity . Therefore, we studied the ferroelectric property of the nanocomposite films . The nanocomposite thin films possess better ferroelectric property than the pure PVDF-TrFE thin films , as demonstrated by the ferroelectric hysteresis curves. The remanent polarizations are 13.59 and 13.94 μC/cm 2 after the doping of 1.0 wt% BT and 1.0 wt% BT-Pdop, respectively, which are about twice that of neat PVDF-TrFE. The piezoelectric β -ferroelectric phase increases with doping, according to X-Ray Diffraction analysis. In addition, the images of polarized optical microscopy and atomic force microscopy also reveal significant enhancement in crystallinity . The neat PVDF-TrFE is a semicrystalline polymer and the size of crystalline spherulites increases with the addition of BT and BT-Pdop nanoparticles. However, even the crystallinity of PVDF-TrFE considerably improved with polydopamine interfacial modification of BT, the increase of remanent polarization due to Pdop is only marginal. We infer that there are other defects at interfaces of BT-Pdop doped PVDF-TrFE nanocomposites which counteract the beneficial effect of the polar OH of polydopamine. Considerable enhancement on ferroelectric property of BT-Pdop doped PVDF-TrFE nanocomposites is expected after these issues are addressed.