查找使用阿拉丁产品的科研文献

High selectivity of new thiourea-modified resins for gold: Adsorption performance, mechanism, and recovery

Chaopeng Liu,Zhongxian Song,Yanli Mao,Xiaole Yan,Zhaoyang Li,Yuzhong Liu,Mengxia Ma,Haiyan Kang,Xu Yan,Deming Gu,Xia Zhang,Zhenzhen Huang

A thiourea-modified weak base anion exchange resin, ZGA451 (thiourea@ZGA451), was prepared. Thiourea@ZGA451 exhibited excellent potential for Au(III) adsorption. The maximum adsorption capacity of Au(III) by thiourea@ZGA451 was 995.6 mg/g at 298 K. The adsorption process followed the Freundlich and pseudo-second-order models, which are monolayer and chemisorption adsorption, respectively. The adsorption mechanism of Au(III) on thiourea@ZGA451 involves electrostatic attraction, chelation, and redox. Thermodynamic experiments showed that the reaction exhibited spontaneous endothermic behavior. Thus, thiourea@ZGA451 possesses outstanding Au(III) adsorption properties.

2D Zn-Porphyrin-Based Co(II)-MOF with 2-Methylimidazole Sitting Axially on the Paddle–Wheel Units: An Efficient Electrochemiluminescence Bioassay for SARS-CoV-2

Yi-Xuan Li,Jing Li,Dunru Zhu,Ju-Zheng Wang,Guo-Fang Shu,Junji Li,Sheng-Li Zhang,Xue-Ji Zhang,Serge Cosnier,Hai-Bo Zeng,Dan Shan

High electrocatalytic activity with tunable luminescence is crucial for the development of electrochemiluminescence (ECL) luminophores. In this study, a porphyrin-based heterobimetallic 2D metal organic framework (MOF), [(ZnTCPP)Co 2 (MeIm)] (1), is successfully self-assembled from the zinc(II) tetrakis(4-carboxyphenyl)porphine (ZnTCPP) linker and cobalt(II) ions in the presence of 2-methylimidazole (MeIm) by a facile one-pot reaction in methanol at room temperature. On the basis of the experimental results and the theoretical calculations, the MOF 1 contains paddle–wheel [Co 2 (-CO 2 ) 4 ] secondary building units (SBUs) axially coordinated by a MeIm ligand, which is very beneficial to the electron transfer between the Co(II) ions and oxygen. Combining the photosensitizers ZnTCPP and the electroactive [Co 2 (-CO 2 ) 4 ] SBUs, the 2D MOF 1 possesses an excellent ECL performance, and can be used as a novel ECL probe for rapid nonamplified detection of the RdRp gene of SARS-CoV-2 with an extremely low limit of detection (≈30 aM).

A “bottle-around-ship” method to encapsulated carbon nitride and CdTe quantum dots in ZIF-8 as the dual emission fluorescent probe for detection of mercury (II) ion

Liu Piaotong,Hao Rusi,Sun Wenliang,Lin Ziyi,Jing Tianfeng,Yang Haizhen

A facile and efficient “bottle-around-ship” approach for preparing the ratiometric fluorescent probe has been developed by encapsulating the red-colored fluorescence CdTe quantum dots (QDs) and blue-colored fluorescence graphitic carbon nitride quantum dots (g-CNQDs) into the zeolitic imidazolate metal–organic frameworks (ZIF-8) in one step. At a single excitation of 360 nm, the obtained probe ZIF-8@g-CNQD/CdTe shows the dual-emission peaked at 450 and 633 nm, respectively. The red emission of CdTe QDs is selectively quenched by the Hg 2+ , whereas the blue fluorescence of g-CNQDs as an internal reference is insensitive, resulting in an apparent color transformation from pink to blue for special recognition of Hg 2+ . By this approach, the relative fluorescence intensity ratio ( F 633 / F 450 ) decreased linearly with increasing Hg 2+ concentration in the 0.2–3.5 μM range with a low limit of detection (LOD) of ~ 46 nM. Therefore, we demonstrate that this “bottle-around-ship” process provides a new strategy for the construction of ratiometric fluorescent Hg 2+ probes with good simplicity, high efficiency, and excellent stabilities. Moreover, the obtained Hg 2+ fluorescent probe shows good results in the detection of actual samples. Graphical abstract

Preparation of covalently bonded liposome capillary column and its application in evaluation of drug membrane permeability

Hui Jiang,Shi-Jun Yin,Xu Wang,Min Lu,Hao Zhang,Feng-Qing Yang

Two liposomes , including 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) + 1,2-dimyristoyl- sn -glycero-3-phosphoethanolamine (PE) + cholesterol (Chol) (DSPC/PE/Chol liposomes) and soybean lecithin (SPC) + PE + Chol (SPC/PE/Chol liposomes), were prepared and fixed on the inner wall of capillary column by using the adhesion of polydopamine (PDA) membrane and the cross-linking property of glutaraldehyde (GA). The immobilized liposome capillary column (ILCC) has good repeatability and stability based on the electrophoretic mobility of analyte . A CE method based on the immobilized liposome capillary column chromatography (ILCCC) was successfully developed to study the retention behavior of drugs on ILCC, and the logarithm of retention factor (log k ) of neutral and ionic drugs were determined. The results show that the log k measured by the ILCCC based on two liposomes have a good linear fitting (R 2 = 0.86). Moreover, the linear relationship between ILCCC system and other related research systems (octanol-water system and immobilized artificial membrane (IAM)) was analyzed, and the results indicate that SPC/PE/Chol ILCCC, DSPC/PE/Chol ILCCC and IAM systems have good fitting results, R 2 values are 0.86 and 0.78, respectively. In addition, the normalization coefficients of ILCCC and IAM systems obtained by the linear free energy relationship (LFER) analysis are close and the d value is small. In short, the ILCCC is a simple and feasible method for studying drug membrane permeability.

Iron and nitrogen co-doped graphene quantum dots as highly active peroxidases for the sensitive detection of L-cysteine

Xiaochun Deng,Jingwen Zhao,Yao Ding,Hongliang Tang,Fengna Xi

As an alternative to natural enzymes, peroxidase nanozymes have shown great potential in the fields of sensing, drug delivery, and tumor treatment. However, obtaining peroxidase nanozymes with high catalytic activity, simple synthesis, and low cost is still a huge challenge. Herein, we demonstrate facile synthesis of iron and nitrogen co-doped graphene quantum dots (Fe,N-GQDs), which possess high peroxidase activity. With hemin being a precursor, Fe,N-GQDs can be easily synthesized with a high production yield (74%) using a one-step hydrothermal process. The as-prepared Fe,N-GQDs exhibit uniform size (2.9 nm), good water dispersibility and bright yellow-green fluorescence (an absolute fluorescence quantum yield of 12.5%). In particular, Fe,N-GQDs exhibit very high peroxidase-mimicking activity and can rapidly oxidize peroxidase substrates 3,3′,5,5′-tetramethylbenzidine (TMB) to produce blue oxidized TMB (oxTMB) in the presence of H2O2. In comparison with a natural enzyme horseradish peroxidase (HRP), the Fe,N-GQD nanozyme has a lower Michaelis constant (Km) and a higher maximum reaction rate (Vmax), indicating higher substrate affinity and faster reaction rate. Selective and sensitive colorimetric detection of L-cysteine (L-Cys) is realized in terms of its ability to reduce oxTMB and to react with H2O2. The linear range for the detection is 0.5–50 μM with a limit of detection (LOD) of 140 nM. In addition, the detection of L-Cys in compound amino acid tablets is also realized.

Nano-materials enhanced protectants for natural stone surfaces

Xie Zaixin,Duan Zhuoqi,Zhao Zhanqiang,Li Ruheng,Zhou Bao,Yang Dequan,Hu Yongmao

Most heritage buildings and monuments are constructed out of natural stones which suffer irrevocable degradation when undergoing wet weathering, bowing, and dissolution in outdoor conditions. Self-cleaning treatments are effective for stone protecting. Herein, nano-materials which provide enhanced protectants for Marble, Qingshi and Hedishi were prepared. Inherent microscale interstices and holes exist on polished natural stone surfaces. When treated by a commercial protectant, 101S, the surfaces were hydrophobic but not self-cleaning. Colloidal protectants were prepared by dispersion of Al 2 O 3 and SiO 2 nano-powder in 101S, respectively. Self-cleaning stone surfaces were achieved after treated by the protectants, meanwhile, the interstices and holes were reserved as much as possible. The principle of the as- prepared protectants is penetrating and crosslinking on the stone surfaces as well as the inner surfaces of the interstices and holes. The reserving of the micro interstices and holes is important since the breathability of the stones is remained. The self-cleaning surfaces showed good thermal stability below 250 °C. Meanwhile, changes of color and gloss of the treated stone surfaces are in the acceptable range.

A fluorescence aptasensor based on GSH@GQDs and RGO for the detection of Glypican-3

Huixue Wang,Jinya Liu,Wei Chen,Jintong Na,Yong Huang,Guiyin Li

Glypican-3 (GPC3), a heparin sulfate proteoglycan, is a potential diagnostic and therapeutic target for hepatocellular carcinoma. In this paper, a novel fluorescent aptasensor for GPC3 detection is constructed via [email protected] quantum dots–labeled GPC3 aptamer ( [email protected] Apt ) as a fluorescence probe. First, [email protected] is screened out with higher fluorescence intensity, which emits bright blue fluorescence under ultraviolet light. Then, the fluorescence-labeled [email protected] Apt probe is formed by the combination of amination GPC3 Apt and [email protected] using EDC/NHS coupled reaction. Under hydrogen bond and π-π interaction/stacking, the fluorescence of [email protected] Apt could be quenched by reductive graphene oxide (RGO) with the help of the photoinduced electron transfer and the fluorescence resonance energy transfer mechanism. In the presence of GPC3, the [email protected] Apt specifically recognizes and binds to GPC3, giving rise to the change of secondary structure of GPC3 Apt to form the GPC3/GPC3 Apt [email protected] complex, which would lead to the disintegration of the [email protected] Apt -RGO compound. Therefore, the energy transfer process is blocked and the fluorescence intensity is restored, enabling a highly sensitive response to GPC3. When the concentration of GPC3 is from 5.0 ng/mL to 150.0 ng/mL, the fluorescence recovery rate is well linearly related to GPC3 concentration with the limit of detection of 2.395 ng/mL (S/N = 3). This strategy shows recoveries from 98.31% to 101.89% in human serum samples and provides simple, fast and cheap analysis of GPC3, which suggests that it has great potential applications in clinical diagnosis for hepatocellular carcinoma.

Depression and anxiety in patients with active ulcerative colitis: crosstalk of gut microbiota, metabolomics and proteomics

Xiaomin Yuan,Biqing Chen,Zhenglan Duan,Ziqian Xia,Yang Ding,Tuo Chen,Huize Liu,Baosheng Wang,Bolin Yang,Xiaoyong Wang,Shijia Liu,Jin-Yong Zhou,Yajun Liu,Qiong Wang,Zhaofeng Shen,Jun Xiao,Hongtao Shang,Weiwei Liu,Guoping Shi,Lei Zhu,Yugen Chen

Exo III-Catalyzed Release of a Zn2+-Ligation DNAzyme to Drive the Strand Displacement Reaction and Gold Aggregation for the Homogeneous Bioassay of Kanamycin Antibiotics

Yiming Xie,Haiyan Wang,Xinyue Yuwen,Guosong Lai

Herein, we combine the exonuclease III (Exo III)-catalyzed release of a Zn2+-dependent ligation DNAzyme with the DNAzyme-driven strand displacement reaction (SDR) to develop a novel homogeneous colorimetric bioassay method for kanamycin (Kana) antibiotic detection. Upon the biorecognition reaction between Kana and a designed hairpin DNA, the DNAzyme-containing strand can be catalytically released by Exo III. Then, this DNAzyme will catalyze the ligation of two oligonucleotides to cause a SDR and the aggregation of gold nanoparticles (Au NPs) labeled by two linker DNA strands. Due to the aggregation of Au NPs for colorimetric signal transduction and the Exo III and SDR-assisted dual signal amplification, this method shows a wide linear range of 5 orders of magnitude and a very low detection limit down to 8.1 fg mL–1. Together with its excellent selectivity, repeatability, reliability, and convenient manipulation, the proposed method shows a great potential for the food quality monitoring application.

Construction of gold nanoparticles by tubular polysaccharide from black fungus and their apoptosis-inducing activities in HepG2 cells

Haoying Song,Na Hu,Ziwei Gao,Baohui Zhang,Junjie Hu,Zhenpeng Qiu,Guohua Zheng,Cong Chang,Yan Meng

Gold nanoparticles (AuNPs) with size of 12 ~ 25 nm were loaded on the dendritic nanotubes (DNTs), which were self-assembled by the triple-helix polysaccharides from black fungus (AF1). The characterization results proved that the AuNPs were dispersed on the surface of DNTs without affecting their tubular structure. Due to the dendritic structure, the loading content of AuNPs could arrived at 46.4%. Moreover, the potential anticancer activities of the complex (DNT-Au) were evaluated by the induction of apoptosis in HepG2 cells. It was found DNT-Au could be taken up by cells and enter into lysosomes, further inducing apoptosis in HepG2 cells by ROS-mediated mitochondrial dysfunction. This work was benefit for the development of natural polysaccharide as a substrate to stabilize nanoparticles in biomedical fields.

N-Vinyl pyrrolidone and undecylenic acid copolymerized on silica surface as mixed-mode stationary phases for reversed-phase and hydrophilic interaction chromatography

Chao Fan,Bei Liu,Hui Li,Kaijun Quan,Jia Chen,Hongdeng Qiu

In this work, three new mixed-mode stationary phases were prepared, based on different ratio of N-vinyl pyrrolidone (NVP) copolymerized together with undecylenic acid (UA) on silica microspheres surface without silanization, which named Sil@NVPUA series. The combination of NVP and UA rendered the Sil@NVPUA suitable for reversed-phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC), and shown excellent methyl, planar, isomers and ion selectivity. Five types of model analytes including eight polycyclic aromatic hydrocarbons, six alkylbenzenes, eight nucleosides and nucleobases, seven ginsenosides and five oxazolidinones can be well separated on this stationary phase. The preparation method of NVP and UA modified silica-based stationary phase is simple, and it also provides a new idea for the design of synthetic polymers to develop mixed-mode chromatography.

One-pot synthesis of a peroxidase-like nanozyme and its application in visual assay for tyrosinase activity

Shuangqin Li,Di Liu,Bingyan Wu,Huipeng Sun,Xiaoyan Liu,Haixia Zhang,Nana Ding,Lan Wu

Both single-atom nanozymes (SAzymes) and protein-template metal nanoparticles have attracted comprehensive attention in several respects owing to their excellent catalytic performance, green facile synthesis process, and robustness. Herein, the peroxidase-like activity of single-atom copper anchored on bovine hemoglobin-template gadolinium nanoparticles (Cu, [email protected] FITC NPs) were successfully synthesized and two sensitive turn-on fluorescence strategies for tyrosinase (TYR) activity sensing were proposed for the first time. For strategy Ⅰ, TYR sensing was carried out from 1.00 to 7.80 U/mL with the detection limit (LOD) of 0.20 U/mL based on the fluorescence resonance energy transfer (FRET) between the fluorescein isothiocyanate (FITC) and the in situ generated polydopamine dots (PDA-dots). For strategy Ⅱ, The LOD of TYR was 0.05 U/mL with the linear range of 0.40–19.70 U/mL based on the elimination of inner-filter effect (IEF) between FITC and the reaction product (RC) of phenol and 4-Aminoantipyrine (AAP). The smartphone-assisted sensing platform was applied to construct the on-site detection of TYR with both strategies. The developed probe possessed good selectivity and was successfully utilized to TYR detection in serum samples.