Molecular Catalysis
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2021
·
IF 5.062
Yanyan Guo,Yichun Dong,Zhigang Lei,Zhixue Liu,Jiqin Zhu
The catalytic performance of Pd-N/Silicon Dioxide/Cordierite (Pd-N/SD/C) ( N = Ga and Ag) bimetallic monolithic catalysts for 2-ethylanthraquinone (eAQ) hydrogenation was investigated. Catalyst characterization by HRTEM, XPS, and TPR reveal that Pd-Ga/SD/C can form an alloy structure to produce significant synergetic effects. Moreover, the use of different Pd/Ga mass ratio in catalysts reveals that when the mass ratio of Pd and Ga/Ag = 2:1, Pd-Ga/SD/C obtains the highest yield of H 2 O 2 and selectivity toward active quinones, which can reach 7.4 g L −1 and 90%. Moreover, to have a deep understanding of the eAQ-PdN(1 1 1) or eAQ-Pd(1 1 1) interaction mechanism, the calculation of eAQ adsorption on Pd-N/SD/C catalysts surface was performed by density functional theory (DFT). It is shown that the higher catalytic activity over Pd-Ga/SD/C is due to the stronger carbonyl group of eAQ adsorption on Pd 3 Ga 1 (1 1 1).
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MATERIALS RESEARCH BULLETIN
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2021
·
IF 4.641
Haodong Tang,Wujian Zhang,Yue Meng,Bo Xie,Zheming Ni,Shengjie Xia
In this paper, M/CeO 2 (M=Pt, Ag, Au) photocatalysts were prepared and used for visible light degradation of methyl orange (MO) with H 2 O 2 as a sacrificial reagent. Utilizing X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM), N 2 physical adsorption (BET), X-ray photoelectron spectroscopy (XPS), photocurrent characterization and electrochemical impedance spectroscopy, etc., the structure, morphology, chemical state, and optical properties of the catalyst were investigated. The effects of the amount of catalyst, the initial concentration of methyl orange, the pH value of the solution and the number of reuses on the photocatalytic degradation efficiency of MO were studied. The results showed that under optimized reaction condition of 15 mg 2Pt/CeO 2 catalyst, the initial concentration of MO was 20 mg/L, pH=5, the reaction time was 195 min and the amount of H 2 O 2 was 0.2 mL, the degradation percentage of MO reached 75.8%. The main active species of photodegradation are hydroxyl radicals and superoxide radicals, which was determined by free radical capture experiments and combined electron spin resonance (ESR). The photocatalytic mechanism based on work function difference and electron transfer was also discussed in detail.
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Journal of Environmental Chemical Engineering
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2021
·
IF 5.909
Shaoru Liu,Weizi Zhang,Peng Zhu,Songlin Zuo,Haian Xia
The study reports a facile synthesis of Ag-g-C 3 N 4 /AC composites with highly photocatalytic activity and good adsorption capacity by an impregnation-thermal polycondensation process. The resulting Ag-g-C 3 N 4 /AC composites were used for treatment of different pollutants in water including Rhodamine B (RhB), Cr(VI) ions and pathogens . When the precursor mass ratio of urea and AC was 2:2, the resultant Ag-g-C 3 N 4 /AC catalyst showed the best photocatalytic performances. In particular, the composite photocatalysts exhibited highly bactericidal efficiency, which could reach 99.9% after 120 min of irradiation. The higher photocatalytic performances of Ag-g-C 3 N 4 /AC composites were attributed to the surface plasmon resonance (SPR) effect of Ag nanoparticles (NPs) together with the interfacial synergistic effects. Meanwhile, AC not only exhibited excellent adsorption capacity, but also decreased aggregation of g-C 3 N 4 , which could enhance the separation efficiency of photogenerated charge carriers. It was uncovered through Electron Spin Resonance (ESR) and radical scavenger experiments that • OH radicals, • O 2 − and h + participate in the RhB degradation under the visible light. This work shows that the high-efficient and stable Ag-g-C 3 N 4 /AC composites have a great potential in the treatment of organic pollutants , toxic heavy metals and pathogenic bacteria by adsorption/photocatalysis for practical water treatment .
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CELLULOSE
·
2021
·Vol. 28
·期 11
·7389-7404
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IF 5.044
Xu Jiangtao,Shang Songmin,Gao Wei,Zeng Ping,Jiang Shouxiang
Although strategies of compositing noble materials and Zeolitic imidazolate frameworks (ZIFs) have been used to enhance the performance of ZIF-based surface-enhanced Raman scattering (SERS) substrates, the enhancement process still remains unclear and the sampling process with powder-form substrates is challenging for practical applications. In this study, a flexible SERS substrate with silver (Ag) nanoparticle decorated ZIF-67 as the active materials and cotton fabric as the supporting framework is developed with a facile method in two steps. The proposed flexible SERS substrate not only can reduce difficulties during the sampling process, but also expands future applications for sampling towards irregular target substances. Meanwhile, the enhancement mechanism has been investigated by using Methylene Blue to probe the molecular interactions. The constructed SERS substrate shows the highest enhancement factor of 6.25 × 10 6 and an excellent detection sensitivity with a limitation of detection (LoD) of 10 –14 M/L. Because of its excellent performance in SERS tracing, the proposed SERS substrate shows exceptional ability in detecting and identifying phenol-soluble modulins and is considered to be a label-free approach that requires no adding markers/tags or antibodies. The proposed substrate expands the potential applications of SERS technology for rapid detection of bacterial toxins during clinical diagnoses and treatment. Graphic abstract Ag decorated ZIF-67 particles are anchored onto cotton fabric to fabricate flexible SERS substrates. The proposed flexible SERS substrate achieves high SERS activity with high enhancement factor, low LoD, good reproducibility and stability. The flexible SERS substrate shows great potential in detection and identification of Phenol-soluble modulin.
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RSC Advances
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2021
·Vol. 11
·期 27
·16339-16350
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IF 3.361
Mengkui Ding,Ling Zha,Hui Wang,Jinyao Liu,Peiwu Chen,Yuefeng Zhao,Lan Jiang,Yuhao Li,Ruizhuo Ouyang,Yuqing Miao
A three-dimensional (3D) frogspawn-like structure was achieved by simply coating nano-carbon outside silver nanospheres (Ag@C NFS) and used as a probe to capture the anti-carcinoembryonic antigen for the electrochemical immunosensing of carcinoembryonic antigen (CEA), a typical biomarker of several diseases such as gastric cancer, intestinal cancer and colon cancer. Moreover, Ag@C nanocables (Ag@C NCs) were aslo synthesized. By comparison, the globular 3D frogspawn-like structure endowed Ag@C NFS with a larger surface area, which is preferred to improve the capability of loading antibodies, higher water solubility, better biocompatibility and improved electrical conductivity, which was likely attributed to the synergistic effects of Ag and crystalline graphite carbon and the different structure with more hydroxyl groups exposed. Therefore, the resultant Ag@C NFS was used as an electrochemical immunosensing platform to fabricate a label-free immunosensor for the analysis of CEA, which showed an excellent immunosensing performance with a wide linear CEA detection range from 0.0001 ng mL−1 to 100 ng mL−1 and a low detection limit of 5.12 pg mL−1. In particular, the good reproducibility, high stability and specificity of the proposed immunosensor ensured the successful application in the quantitative determination of CEA in cancerous human serum samples, providing a promising alternative to detect other biomarkers.
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PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2021
·
IF 7.46
Wen Shou,Shuangting Yang,Yueliang Wang,Bin Qiu,Zhenyu Lin,Longhua Guo
The portable and instrument-free sensing device for quantitative detection is of significant applications in resource constrained countries and regions. Here, a colorful height readout device formed by agarose hydrogel doped with gold nanobipyramids (AuNBPs@AG) is developed for the determination of hydrogen peroxide (H 2 O 2 ) content. The responsive mechanism is based on H 2 O 2 guided etching of AuNBPs, which causes the plasmon-mediated color change of the AuNBPs@AG hydrogel filled in plexiglass tube from top to bottom. We demonstrate the height of color-changed hydrogel is quantitatively related to the concentration of H 2 O 2 . The agarose hydrogel, as the carrier material for loading AuNBPs, guarantees the stability of AuNBPs and promotes the separation of complex samples. The method shows a good linear relationship in four ranges of H 2 O 2 concentrations of 20 − 100 μM, 200 − 1000 μM, 1 − 10 mM and 10 − 100 mM. Compared with previous methods, using this inexpensive and easy to operate device for H 2 O 2 detection can effectively reduce the interference of the color background, overcome the problem of the nanoparticles aggregation, and eliminate the need for expensive and sophisticated detection instruments. The practicality of the method is demonstrated via the analysis of commercial products such as contact lens solution and hair dye with satisfactory results. Our work provides a novel path for developing the height-readout quantitative devices with integrating hydrogels and plasmonic nanomaterials.
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Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 30
·9492-9498
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IF 7.393
Jinmin Wang,Xin Xu,Limin Zhao,Bing Yan
Covalent organic frameworks (COFs) demonstrate a new trend in the field of chemical sensing mainly due to their potential for functional modification, defined pore environment and good chemical stability. Exploring functionalized-COF materials as chemosensors with low detection limits and high selectivity for biologically and environmentally important analytes is a campaign in this field. In this work, the incorporation of polyoxometalate (POM, Eu4W8) into the crystalline architecture a COF (EB-TFP) generates a functional composite material Eu4W8@EB-TFP. This material combines the merits of POM and COF together; it endows COF with outstanding luminescence properties and effectively broadens the sensing application of COF. It points out a new direction to employ POM-functionalized COF materials as efficient chemosensors to monitor trace amounts of Ag+ in environmental and CG (hepatocellular carcinoma biomarker) in biological systems. This work provides new insights into COF-based sensors and inspires the development of more versatile tools for analytical applications.
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MICROCHEMICAL JOURNAL
·
2021
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IF 4.821
Chuhong Zhu,Qiangsheng Zhao,Xiujuan Wang,Zhongbo Li,Xiaoye Hu
Concentration of analyte molecules on or nearby plasmonic nanostructures is crucial for sensitive SERS detection. In this paper, a functional SERS system made of Ag-nanocubes/graphene-oxide/Au-nanoparticles (Ag-NCs/GO/Au-NPs) composite film on a hydrophobic surface is constructed for effective accumulation and thus sensitive detection of target analyte in water. High density of plasmonic hotspots are generated between Au nanoparticles-assembled film and the Ag-NCs/GO hybrid, remarkably improving SERS activity. The hydrophobic surface is used to concentrate the analyte molecules in an aqueous droplet onto the Ag-NCs/GO/Au-NPs film during the droplet drying process. The hydrophilic graphene oxide sheets can adsorb analyte molecules nearby the plasmonic nanoparticles. The corners of Ag nanocubes, and the narrow nanogaps between neighboring palsmonic nanoparticles, could provide high density of hotspots for high SERS activity. Due to the effective accumulation of analyte molecules on/nearby hotspots, sensitive SERS detection of pesticides has been realized. The fabricated SERS platform was employed to successfully detect an aqueous solution of rhodamine 6G with an ultralow concentration (0.5 pM), conforming the high SERS sensitivity. To show the potential for practical application, SERS detection of pesticides such as thiram and thiabendazole in drinking-water was realized with limits of detection (LODs) ~ 0.37 ppb and ~ 8.3 ppb respectively. The functional SERS system may have promising applications in inspection of food safety, monitoring environmental pollutants and so on.
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BIOCHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 3.475
Hong Zhang,Chuance Cheng,Nalin Dong,Xiaoming Ji,Jiandong Hu
S1 nuclease plays an important role in DNA transcription, recombination and repair. Here, we synthesized a positively charged [email protected] core-shell nanoparticles ((+) [email protected] CSNPs) and used as highly stable and enhanced fluorescence quenching platform for one-step S1 nuclease activity detection. In the sensor, fluorophore labeled DNA was used as signal probe and its fluorescence signal could be effectively quenched based on the electrostatic interaction of it with (+) [email protected] CSNPs. In the presence of S1 nuclease, DNA probe was hydrolyzed into DNA fragments and cannot interact with (+) [email protected] CSNPs, inducing an obvious fluorescence signal increase that was proportional with S1 nuclease concentration in the range of 2.5 × 10 −4 –3.0 × 10 −2 U/mL. The enhanced quenching efficiency of (+) [email protected] CSNPs paved the way for sensitive S1 detection with a detection limit of 6.0 × 10 −5 U/mL. Moreover, the high stability of such nanocomposite can achieve the one-step detection of S1 in complex solution containing salt, protein or other metal ions. In addition, the method also exhibited high selectivity for nuclease detection, making our sensing platform has a potential application value in bioanalysis and clinical diagnosis.
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APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Jie Yang,Gao Song,Ling Zhou,Xinyue Wang,Lijun You,Jumei Li
In this study, we successfully constructed Ag/TiO 2 core-shell nanoparticles through an easy wet chemistry method for SERS study. Compared to Ag cores, the Ag/TiO 2 core-shell nanoparticles presented higher SERS sensitivity, owing to a synergistic SERS enhancement arising from electromagnetic field effect of Ag cores and chemical enhancement of TiO 2 shells. Furthermore, uniform TiO 2 shells were able to effectively protect the internal Ag cores against destruction in external environment and thus storage stability of Ag/TiO 2 nanoparticles was prominently improved. The as prepared Ag/TiO 2 core-shell nanoparticles were applied to quantitatively sense tetramethylthiuram disulfide (TMTD) in solution using a portable Raman spectrometer. The results showed that the SERS intensity of 563 cm −1 assigned to S-S stretching mode had a good linear relationship with the concentration of TMTD with the correlation coefficient (R 2 ) of as high as 0.99 and the detection limit of as low as 1.15 × 10 −10 M. Consequently, the prepared Ag/TiO 2 nanoparticles present specially advantage of quantifying S-S groups by SERS, because the TiO 2 shell could act as a spacer between Ag cores and TMTD molecules and keep the S-S bonds intact.
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MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 10
·1-9
·
IF 6.232
Wei Shengnan,Li Juan,He Jingya,Zhao Wei,Wang Feng,Song Xiuling,Xu Kun,Wang Juan,Zhao Chao
A rapid and sensitive colorimetric assay is described for Salmonella typhimurium ( S. typhimurium ) detection using urea/phenol red impregnated test paper. Aptamer-modified Fe 3 O 4 @Ag multifunctional hybrid nanoprobes (apt-Fe 3 O 4 @Ag NPs) were used to specifically captured S. typhimurium ; the nanoprobes were quickly etched by H 2 O 2 to form Ag + . The generated Ag + can inhibit the urease-catalyzed hydrolysis reaction of urea to produce NH 4 + . Consequently, the as-prepared test paper displayed a yellow color. In the presence of S. typhimurium , the target bacteria can cause aggregation of apt-Fe 3 O 4 @Ag NPs, and the deposited Ag on the nanoprobe’s surface is shielded against H 2 O 2 -induced oxidative decomposition leading to reduced Ag + production. The catalytic activity of urease cannot be inhibited completely by inadequate amount of Ag + . An obvious color change from yellow to pink can be monitored directly using our test paper as a result of increased NH 4 + . The entire assay procedure could be completed within 1 h. A limit of detection of 48 cfu/mL is achieved with a linear range of 1 × 10 2 to 1 × 10 6 cfu/mL. The recoveries of S. typhimurium spiked in pure milk samples were 92.48–94.05%.
Schematic diagram of the proposed colorimetric assay for S. typhimurium detection based on etching of bifunctional apt-Fe 3 O 4 @Ag NPs and inhibiting catalytic activity of urease by Ag + . A color change from yellow to pink can be observed and correlated to the concentration of S. typhimurium.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2020
·
IF 7.1
Yu Ling,Lei Wang,Xing Yue Zhang,Xiao Hu Wang,Jiao Zhou,Zhe Sun,Nian Bing Li,Hong Qun Luo
For small size metal nanoclusters, it is expected that template ligand will play an essential role in regulating the properties and structure. Using histidine (His) templated Ag nanoclusters and glutathione (GSH) and dihydrolipoic acid (DHLA) protected silver nanoclusters as models, due to the different electron donating abilities of different ligands, two silver nanoclusters with similar sizes have fluorescence emission peaks at different wavelengths. Furthermore, dopamine (DA) is a good electron donor, but is easily oxidized to dopaquinone, which can act as an electron accepter. Therefore, with addition of DA, which is easily oxidized by dissolved oxygen, the fluorescence of His-Ag nanoclusters quenches. Meanwhile, the ligands of GSH-DHLA-Ag nanoclusters contain sulfhydryl group, which has stronger reducing ability and stronger electron donating ability. Therefore, even in the presence of dopaquinone, the electron-donating effect of the ligand of the GSH-DHLA-Ag nanoclusters on the metal cores does not decrease significantly. Moreover, the addition of DA causes a certain degree of aggregation of GSH-DHLA-Ag nanoclusters, and the fluorescence intensity is enhanced due to the aggregation-inducing emission enhancement effect. Based on two types of silver nanoclusters, a ratiometric fluorescent sensor for DA analysis has been established. The linear range is 0−800 nM, and the limit of detection based on 3δ/s is 10 nM.
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