Yan Shi

Chinese Academy of Sciences, Peping, Beijing, China

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Publications (33)84.85 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: In this study, a facile method to sensitively detect melamine and highly improve the peroxidase-like activity of bare gold nanoparticles (Au NPs) at the same time is proposed for the first time. It is interesting to find that the addition of melamine could improve the peroxidase-like activity of Au NPs. By coupling with 3,3',5,5'-tetramethlybenzidine (TMB)-H2O2 chormogenic reaction, a novel method for colorimetic detection of melamine is developed. The detection limit of this method is as low as 0.2nM with the help of UV-vis spectroscopy and 0.5µM by naked-eye observation, both which are far below the US food and Drug Administration estimated melamine safety limit of 20µM. In addition, the present method is successfully applied for the detection of melamine in raw milk and milk powder. More importantly, the proposed method could also improve the peroxidase-like activity of Au NPs, which may not only provide a new approach to develop effective nanomaterials-based mimetic enzyme, but also irradiative to develop new applications for Au NPs in varieties of cost-effective and simple sensors in medicine, biotechnology and environmental chemistry.
    Biosensors & bioelectronics 04/2014; 60C:286-291. · 5.43 Impact Factor
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    ABSTRACT: NiCo2O4 nanoflake composites were synthesized by using DNA molecules as templates via in-situ assembly and subsequent thermal treatment. The obtained NiCo2O4 composites were characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray powder diffraction, thermogravimetric analysis, and X-ray photoelectron spectroscopy. Cyclic voltammetry and chronopotentiometry tests were used to investigate the electrochemical properties of the as-prepared composites. Superior performances with a good specific capacitance (1468 F/g), an extraordinary rate capability (64.9% capacity retention at 16 A/g) and an excellent cycling stability (85.5% retention after 5000 cycles) were achieved. The DNA templates were introduced as the binder of NiCo2O4 and as the conductive matrix to facilitate the electron transmission between electroactive materials and outside current collectors, which resulted in the excellent electrochemical performances of the synthesized NiCo2O4 composites. It is believed that our NiCo2O4 nanocomposites could be used as effective electrode materials for supercapacitors.
    Electrochimica Acta 03/2014; 121:270–277. · 4.09 Impact Factor
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    ABSTRACT: In this study, a facile method to sensitively detect melamine and highly improve the peroxidase-like activity of bare gold nanoparticles (Au NPs) at the same time is proposed for the first time. It is interesting to find that the addition of melamine could improve the peroxidase-like activity of Au NPs. By coupling with 3,3′,5,5′-tetramethlybenzidine (TMB)–H2O2 chormogenic reaction, a novel method for colorimetic detection of melamine is developed. The detection limit of this method is as low as 0.2 nM with the help of UV–vis spectroscopy and 0.5 µM by naked-eye observation, both which are far below the US food and Drug Administration estimated melamine safety limit of 20 µM. In addition, the present method is successfully applied for the detection of melamine in raw milk and milk powder. More importantly, the proposed method could also improve the peroxidase-like activity of Au NPs, which may not only provide a new approach to develop effective nanomaterials-based mimetic enzyme, but also irradiative to develop new applications for Au NPs in varieties of cost-effective and simple sensors in medicine, biotechnology and environmental chemistry.
    Biosensors & bioelectronics 01/2014; 60:286–291. · 5.43 Impact Factor
  • Sensors and Actuators B Chemical 01/2014; 202:201–208. · 3.84 Impact Factor
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    ABSTRACT: Here, we report a new and facile method to prepare silver nanoparticles (Ag NPs) film for surface-enhanced Raman scattering (SERS)-based sensing. The porous Ni foam was used as a template to generate high quality of Ag NPs by seed-mediated growth of metallic nanoparticles. The preparation process is very economic and environment-friendly, can achieve the recovery of the raw materials. We found that the type of silver-plating solution and the growth time are two key factors to determine the magnitude of SERS signal enhancement. Using rhodamine 6G (R6G) and 4-animothiophenol (4-ATP) as probe molecules, the created Ag NP films exhibited relatively high enhancement ability, good stability, and well reproducibility. The synthesized SERS-active substrate was further used to detect melamine molecules, an illegal additive in infant milk powder, and the limitation of detection can reach 1 μM.
    Applied Surface Science 10/2013; · 2.54 Impact Factor
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    ABSTRACT: In this work, we proposed a facile, environmentally friendly and cost-effective assay for melamine with BSA-stabilized gold nanoclusters (AuNCs) as a fluorescence reader. Melamine, which has a multi-nitrogen heterocyclic ring, is prone to coordinate with Hg(2+). This property causes the anti-quenching ability of Hg(2+) to AuNCs through decreasing the metallophilic interaction between Hg(2+) and Au(+). By this method, detection limit down to 0.15µM is obtained, which is approximately 130 times lower than that of the US food and Drug Administration estimated melamine safety limit of 20µM. Furthermore, several real samples spiked with melamine, including raw milk and milk powder, are analyzed using the sensing system with excellent recoveries. This gold-nanocluster-based fluorescent method could find applications in highly sensitive detection of melamine in real samples.
    Biosensors & bioelectronics 09/2013; 53C:76-81. · 5.43 Impact Factor
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    ABSTRACT: With the widespread application of computer and communication technologies, more and more real-time systems are implemented whose large amounts of time-stamped data consequently require more efficient processing approaches. For large-scale time series, precise values are often hard or even impossible to predict in limited time at limited costs. Meanwhile, precision is not absolutely necessary for human to think and reason, so credible changing ranges of time series are satisfactory for some decision-making problems. This study aims to develop fast interval predictors for large-scale, nonlinear time series with noisy data using fuzzy granular support vector machines (FGSVMs). Six information granulation methods are proposed which can granulate large-scale time series into subseries. FGSVM predictors are developed to forecast credible changing ranges of large-scale time series. Five performance indicators are presented to measure the quality and efficiency of FGSVMs. Four time series are used to examine the effectiveness and efficiency of the proposed granulation methods and the developed FGSVMs, whose results show the effectiveness and advantages of FGSVMs for large-scale, nonlinear time series with noisy data.
    Applied Soft Computing 09/2013; 13(9):3981-4000. · 2.68 Impact Factor
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    ABSTRACT: This study demonstrates a cocaine sensing method employing graphene oxide (GO), gold nanoparticles and a structure switching aptamer, which can fold into a three-way junction in the presence of cocaine. On the observation of gold nanoparticles (Au NPs) induced graphene oxide fluorescence quenching, a structure switching aptamer of cocaine was introduced as the linker between the two parts. Firstly, two fragments of a cocaine aptamer were immobilized covalently onto GO and Au NPs, respectively. Then when the three-way junction formed, the Au NPs were drawn near to the GO surface and induced a fluorescence intensity decrease. The limit of detection was 0.1 μM for cocaine in purified water, and well defined results were also obtained in biological fluids and the specificity experiment, which expands the feasibility of the as-prepared sensor for practical applications.
    The Analyst 08/2013; · 4.23 Impact Factor
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    ABSTRACT: The transportation networks often become uncertain due to the occurrence and development of disasters. In order to select proper paths under uncertain infor- mation, we propose a novel scenario-based approach for emergency path selection. The scenario factors are �rstly analyzed and combined to describe the uncertainty of each path section between two adjacent intersections in emergency transportation networks. Then, according to the fuzzy properties of path sections, the membership transformation algorithm M(1,2,3) is applied in fuzzy evaluation on the scenarios of path sections, which can determine the satisfaction degrees of each path section. Combining the highest sat- isfaction of each section under various scenarios, an optimal multi-attribute vector is constructed to build the scenario-based optimization model for emergency path selection. Finally, a numerical example is shown to illustrate the solution of this approach, whose results show that this approach can produce the paths with maximized overall satisfaction degree in a given con�dence and that the satisfaction degree will increase as the given con�dence decreases.
    International journal of innovative computing, information & control: IJICIC 08/2013; 9(8):293-3305. · 2.93 Impact Factor
  • ICIC Express Letters 07/2013; 7(2):471-478.
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    ABSTRACT: Electrochemical reduction and electrodeposition are two effective methods for the preparation of new nanomaterials for electrochemical sensing. In this work, the reduced graphene oxide-nickel nanoparticles composite (RGO-NiNPs) was synthesized using both methods mentioned above. The fabrication process was simple and easily performed. Then, the RGO-NiNPs composite was characterized by SEM, EDS, and XRD. Furthermore, for the strong catalytic ability of the high-valent oxyhydroxide species (NiOOH) formed in alkaline media, the composite was used as the matrix for nonenzymatic detection of glucose. Comparing with NiNPs modified glassy carbon electrode (NiNPs/GCE), the RGO-NiNPs/GCE showed better sensitivity and stability. A low detection limit of 0.1 µM with a wide linear range from 2 µM to 2.1 mM (R=0.996) was obtained.
    Electroanalysis 04/2013; 25(4). · 2.82 Impact Factor
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    ABSTRACT: In this work, input-to-state stability of Lur’e hyperbolic distributed complex-valued parameter control systems has been addressed. Using comparison principle, delay-dependent sufficient conditions for the input-to-state stability in complex Hilbert spaces are established in terms of linear operator inequalities. Finally, numerical computation illustrates our result.
    Mathematical Problems in Engineering 02/2013; 2013. · 1.38 Impact Factor
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    ABSTRACT: The existence of uncertainties may result in various unexpected disruption events in logistics delivery, which often makes actual delivery operations deviate from intended plans. The purpose of the paper is to develop a combinational disruption recovery model for vehicle routing problem with time windows (VRPTW), trying to handle a variety and a combination of delivery disruption events. Firstly, a novel approach to measure new-adding customer disruption, which considers the real-world participators (mainly including customers, drivers and logistics providers) in VRPTW, is developed. Then the paper proposes methods of transforming various delivery disruptions into the new-adding customer disruption, and determines the optimal starting times of delivery vehicles from the depot to provide a new rescue strategy (called starting later policy) for disrupted VRPTW. Based on the above, a combinational disruption recovery model for VRPTW is constructed and nested partition method (NPM) is designed to solve the proposed model. Finally, computational results are reported and compared with those of previous works, which verifies the effectiveness of the proposed solution and draws some interesting conclusions.
    International Journal of Production Economics 11/2012; 140(1):508–520. · 2.08 Impact Factor
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    ABSTRACT: Water safety is one of the most pervasive problems afflicting people throughout the world. Microcystin, a hepatotoxin produced by cyanobacteria, poses a growing and serious threat of water safety. According to World Health Organization (WHO), the limit of content of microcystin-LR (MC-LR) in drinking water is as low as 1 μg/L; it is thus necessary to explore a sensitive method for the trace detection of microcystins (MCs). Based on the observation of gold nanoparticles (Au NPs) induced graphene oxide (GO) fluorescence quenching, a reliable biosensor was developed here for microcystins detection. MCs could be attached on Au NPs through the interaction with single strand-DNA (ss-DNA) modified on Au NPs, which formed Au-DNA-MCs complexes. These MCs in the complexes could be immunologically recognized by the antibodies adsorbed on GO sheets, as a result, Au NPs were close enough to quench the photoluminescence of GO by the fluorescence resonance energy transfer (FRET). The fluorescence intensity decreased with the increase of MCs as more Au NPs linked onto GO surface. The limit of detection was 0.5 and 0.3 μg/L for microcystin-LR and microcystin-RR (MC-RR), respectively, which satisfies the strictest standard of WHO. Well defined results were also obtained in natural lake water and the specificity experiment. The antibody used here could recognize Adda group, the conservative part of MCs, which allowed the biosensor to detect both single toxin and the total content of MCs existing in the water sample.
    Biosensors & bioelectronics 06/2012; 38(1):31-6. · 5.43 Impact Factor
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    ABSTRACT: Numerous items, small order, and frequent delivery are the characteristics of many distribution centers. Such characteristics generally increase the operating costs of the distribution center. To remedy this problem, this study employs the Entry-Item-Quantity (EIQ) method to identify the characteristic of the cigarette distribution center and further analyzes the importance degree of customers and the frequently ordered products by means of EQ/EN/IQ-B/IK statistic charts. Based on these analyses as well as the total replenishment cost optimization model, multipicking strategies and combined multitype picking equipment allocation is then formulated accordingly. With such design scheme, the cigarette picking costs of the distribution center are expected to reduce. Finally, the specific number of equipment is figured out in order to meet the capability demand of the case cigarette distribution center.
    Mathematical Problems in Engineering 01/2012; 2012. · 1.38 Impact Factor
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    ABSTRACT: Because clean energy and traditional energy have different advantages and disadvantages, it is of great significance to evaluate comprehensive benefits for hybrid power systems. Based on thorough analysis of important characters on hybrid power systems, an index system including security, economic benefit, environmental benefit, and social benefit is established in this paper. Due to advantages of processing abundant uncertain and fuzzy information, vague set is used to determine the decision matrix. Convert vague decision matrix to real one by vague combination ruleand determine uncertain degrees of different indexes by grey incidence analysis, then the mass functions of different comment set in different indexes are obtained. Information can be fused in accordance with Dempster-Shafer (D-S) combination rule and the evaluation result is got by vague set and D-S evidence theory. A simulation of hybrid power system including thermal power, wind power, and photovoltaic power in China is provided to demonstrate the effectiveness and potential of the proposed design scheme. It can be clearly seen that the uncertainties in decision making can be dramatically decreased compared with existing methods in the literature. The actual implementation results illustrate that the proposed index system and evaluation model based on vague set and D-S evidence theory are effective and practical to evaluate comprehensive benefit of hybrid power system.
    Mathematical Problems in Engineering 01/2012; 2012. · 1.38 Impact Factor
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    ABSTRACT: This review highlights recent advanced researches on the assembly of various metallic nanostructures by oligonucleotide and plasmidDNA. The obtained DNA–nanoconjugates show many unique and attractive properties, while this review focuses on their properties related to SERS detection. The applications of DNA-based assemblies in SERS detections were fully commented upon, for the detection ofDNA, proteins, small molecules, and metallic ions. Finally, a concluding section is given, which covers the challenges and scope for DNA assembled nanostructures as well as for the DNAassemblies-related SERS detections.
    Journal of Materials Chemistry 10/2011; 21(42):16675-16685. · 5.97 Impact Factor
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    ABSTRACT: Ni(OH)2 nanoplates were successfully synthesized and in situ assembled on reduced graphene oxide (RGO) nanosheets by a simple one-pot method. This RGO-Ni(OH)2 nanocomposite was characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD), Raman and X-ray photoelectron spectroscopy (XPS). TEM images showed that the composite was round and that leaf-shaped nanoplates with a diameter of about 150 nm assembled on the RGOnanosheets. EDX, XRD, Raman and XPS characterization proved that the constituent parts of the composite were Ni(OH)2 and RGO. Moreover, the amount of Ni(OH)2 assembled on the RGO could be adjusted simply by changing the volume of NiCl2 added to the reactant mixture. For the strong catalytic ability of the high-valent oxydroxide species (NiOOH) formed in alkaline media, the RGO-Ni(OH)2 nanocomposite was used as the matrix for the non-enzymatic detection of glucose. A low detection limit of 0.6 μM with a wide linear range from 2 μM to 3.1 mM (R = 0.9987) could be obtained. The operating simplicity and low expense of fabrication make this Ni(OH)2-based electrode attractive in sensor construction.
    Journal of Materials Chemistry 10/2011; 21(42):16949-16954. · 5.97 Impact Factor
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    ABSTRACT: A superhydrophobic substrate that combines the superhydrophobic condensation effect and high enhancement ability of silver nanoparticle coated zinc oxide nanorods array (Ag@ZnO) is explored for surface enhanced Raman scattering (SERS). The effects of water contact angle and droplet volume on the final SERS signal intensity are also investigated for the first time. Our results indicate the superhydrophobic substrate could exhibit 3-fold signal enhancement more than the ordinary hydrophilic Ag@ZnO substrate due to the superhydrophobic condensation effect. This signal amplification effect is affected by the water contact angle and water droplet volume on the substrate, i.e., (1) the higher the contact angle is, the higher the SERS signal is; (2) the SERS intensity fluctuates as the droplet volume increases, and proper volume, not the largest one, should be chosen to achieve a stronger signal. Most importantly, this superhydrophobic substrate with high signal reproducibility is successfully applied to detect small molecules such as adenine and melamine, with the detection limits of 1 order of magnitude less than those on the hydrophilic Ag@ZnO substrate. It is expected this superhydrophobic SERS substrate can be widely used in the trace analysis in the future.
    The Journal of Physical Chemistry C. 04/2011; 115(20).
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    ABSTRACT: Microcystin-LR (MC-LR) is one of the hepatotoxins produced by cyanobacteria in the eutrophicated fresh water. In this work, the minor groove binding mode of MC-LR to plasmid DNA was explored by using UV and fluorescence spectra, and the binding characteristics of MC-LR for plasmid DNA were calculated via the fluorescence quenching of ethidium bromide (EB) and mole ratio method. Furthermore, atomic force microscopy (AFM) was used to observe DNA morphology change in the presence of MC-LR. With the increasing concentration of MC-LR, circle DNA strands twined gradually to rod condensates. The possible reason for the condensation might be the masking of the electrostatic repulsion between DNA double strands by MC-LR. The present study might provide useful information for the pathopoiesis mechanism of MC-LR. More, because the condensation of DNA could affect the progresses of gene expression and protein transcription, it may implicate another trend to explore the nosogenesis of MC-LR.
    Biomacromolecules 02/2011; 12(3):797-803. · 5.37 Impact Factor

Publication Stats

68 Citations
84.85 Total Impact Points

Institutions

  • 2013–2014
    • Chinese Academy of Sciences
      • State Key Laboratory of Electroanalytical Chemistry
      Peping, Beijing, China
  • 2012–2013
    • Tokai University
      • School of Industrial Engineering
      Hiratuka, Kanagawa, Japan
    • Dalian University of Technology
      • Institute of Systems Engineering
      Lü-ta-shih, Liaoning, China
  • 2010–2013
    • Northeast Institute of Geography and Agroecology
      • State Key Laboratory of Electroanalytical Chemistry
      Peping, Beijing, China