Reversible photoswitching aggregation and dissolution of spiropyran- functionalized copolymer and light-responsive FRET process

Well-defined, reversibly light-responsive amphiphilic diblock copolymer grafted with spiropyran, was prepared by reversible addition–fragmentation chain transfer(RAFT) polymerization. The copolymer self-assembles into polymeric micelles in water and exhibits reversible dissolution and re-aggregation characteristics upon ultraviolet(UV) and visible(Vis)-light irradiation. The fluorescence response of spiropyran immobilized onto the copolymer was light switchable. When nitrobenzoxadiazolyl derivative(NBD) dyes are encapsulated into the core of the micelles, a reversible, light-responsive, dual-color fluorescence resonance energy transfer(FRET) system is constructed and processed, which is well regulated by alternatively UV/vis irradiation. We anticipate these photoswitchable and FRET lighting up nanoparticles will be useful in drug delivery and cell imaging or tracking synchronously.     

Enhanced high temperature cycling performance of LiMn2O4/graphite cells with methylene methanedisulfonate（MMDS） as electrolyte additive and its acting mechanism

The effects of methylene methanedisulfonate(MMDS) on the high-temperature(~50℃) cycle performance of LiMn_2O_4/graphite cells are investigated.By addition of 2 wt%MMDS into a routine electrolyte,the high-temperature cycling performance of LiMn204/graphite cells can be significantly improved.The analysis of differential capacity curves and energy-dispersive X-ray spectrometry(EDX) indicates that MMDS decomposed on both cathode and anode.The three-electrode system of pouch cell is used to reveal the capacity loss mechanism in the cells.It is shown that the capacity fading of cells without MMDS in the electrolytes is due to irreversible lithium consumption during cycling and irreversible damage of LiMn_2O_4 material,while the capacity fading of cell with 2 wt%MMDS in electrolytes mainly originated from irreversible lithium consumption during cycling.     

Insight into the Urea Binding and K166R Mutation Stabilizing Mechanism of TIpB： Molecular Dynamics and Principal Component Analysis Study

Chemoreceptor TlpB（Tlp=transducer-like protein）, which has been demonstrated to respond to pH sensing function, is crucial for the survival ofHelicobacterpylori（H, pylori） in host stomach. Urea was proposed to be essen- tial for TlpB＇s pH sensing function via binding with the Per-ARNT-Sim（PAS） domain of TlpB. Additionally, KI66R mutation of the TlpB protein has also been proven to have a similar effect on TlpB pH sensing as urea binding. Al- though X-ray crystallographic studies have been carried out for urea-bound Tlpl3, the molecular mechanism for the stabilization of TIpB induced by urea binding and K166R mutation remains to be elucidated. In this study, molecular dynamics simulations combined with principal component analysis（PCA） for the simulation results were used to gain an insight into the molecular mechanism of the stabilization of urea on TlpB protein. The formed H-bonds and salt-bridges surrounding Aspll4, which were induced by both urea binding and K166R mutation of TIpB, were im- portant to the stabilization of TlpB by urea. The similarity between the urea binding and K166R mutation as well as their differences in effect has been explicitly demonstrated with computer simulations at atomic-level. The findings may Dave the wav for the further researches of TlpB.     

烟用接装纸质控样品的制备与应用

采用深珠光印字烟用接装纸作为质控样品,用微波消解处理质控样品,以电感耦合等离子体质谱法(ICP–MS)对样品的铬、砷、铅含量进行定值,并进行不确定度评定。利用方差分析评价均匀性,ADF检验评价稳定性。经F检验表明在95%的置信区间,制备的烟用接装纸质控样品均匀性良好;经ADF检验表明,各元素在1%的显著水平下稳定可靠,样品稳定性良好。将烟用接装纸质控样品用于质控,并绘制Levy–Jennings质控图,质控效果良好。     

姜黄素–邻二氮菲–镍配合物修饰电极的制备及其对葡萄糖的催化氧化

研究了姜黄素–邻二氮菲–镍配合物修饰电极对葡萄糖的催化氧化行为。在pH 6.0的磷酸盐缓冲液条件下,姜黄素与邻二氮菲–镍配合物聚合,附着在铂碳电极上制得姜黄素–邻二氮菲–镍配合物修饰电极,该修饰电极对葡萄糖的催化效果优于姜黄素修饰电极。在优化测试条件下,姜黄素–邻二氮菲–镍配合物修饰电极对葡萄糖测定的线性范围为6.0×10–5～3.0×10–3 mol/L,相关系数r=0.997 2。该修饰电极可用于测定血液中的葡萄糖,测定结果的相对标准偏差为2.16%～4.44%(n=10),回收率在98.2%～103.2%之间。该方法准确可靠,可用于测定血液中的葡萄糖。     

SDS改性沸石对碱性品红的吸附性能研究

通过静态实验探讨了表面活性剂十二烷基硫酸钠（SDS）改性沸石吸附碱性品红的影响因素。实验结果表明在投入量为8 g/L、吸附时间为45 min、p H值为6、温度为25℃时,对初始质量浓度100 mg/L碱性品红溶液的去除率可达到96.16%,吸附量为12.02 mg/g;SDS改性沸石吸附碱性品红的吸附性能符合Langmuir型吸附等温线和一级反应动力学模型的特征;热力学分析结果表明,吸附符合自发吸热过程。     

溶(土)洞灌浆材料室内实验研究

采用正交实验法,对中科院广州化灌工程有限公司近年施工的四类溶(土)洞所采用的灌浆材料配比进行了研究,得到优化的室内灌浆材料配方。     

易衍生化温敏高分子刷的制备及其温敏行为研究

温敏材料由于优异的性能和潜在的应用价值而具有良好的发展前景.利用超分子自组装单层(SAM)与表面引发聚合(SIP)技术将2-(2-甲氧乙氧基)甲基丙烯酸乙酯(MEO2MA)与聚乙二醇甲基丙烯酸酯(OEGMA526)的共聚物poly(MEO2MAco-OEGMA526)接枝于金表面,探索了不同引发剂溶液浓度(χIsol)、单体OEGMA526摩尔浓度(C526)与干态膜厚度(d)对该高分子刷性质的影响.应用石英晶体微天平(QCM)对其温敏行为进行研究,结果表明:在χIsol=1%与C526=5%条件下制备的高分子刷,最低临界溶解温度(LCST)为34℃;其LCST由OEGMA526的单体摩尔浓度决定,不受膜厚的影响.该高分子刷在接枝生物素后其与链霉亲和素的结合实验证明,高分子刷末端的羟基为其官能团化提供了契机.该易衍生化温敏高分子刷为发展新型温敏材料提供了研究基础.     

Highly sensitive detection of human cardiac myoglobin using a reverse sandwich immunoassay with a gold nanoparticle-enhanced surface plasmon resonance biosensor

A highly sensitive reverse sandwich immunoassay for the detection of human cardiac myoglobin (cMb) in serum was designed utilizing a gold nanoparticle (AuNP)-enhanced surface plasmon resonance (SPR) biosensor. First, a monoclonal anti-cMb antibody (Mab1) was covalently immobilized on the sensor surface. AuNPs were covalently conjugated to the second monoclonal anti-cMb antibody (Mab2) to form an immuno-gold reagent (Mab2-AuNP). The reverse sandwich immunoassay consists of two steps: (1) mixing the serum sample with Mab2-AuNP and incubation for the formation of cMb/Mab2-AuNP complexes and (2) sample injection over the sensor surface and evaluation of the Mab1/cMb/Mab2-AuNP complex formation, with the subsequent calculation of the cMb concentration in the serum. The biosensor signal was amplified approximately 30-fold compared with the direct reaction of cMb with Mab1 on the sensor surface. The limit of detection of cMb in a human blood serum sample was found to be as low as 10 pM (approx. 0.18 ng mL⁻¹), and the inter-assay coefficient of variation was less than 3%. Thus, the developed SPR-based reverse sandwich immunoassay has a sensitivity that is sufficient to measure cMb across a wide range of normal and pathological concentrations, allowing an adequate estimation of the disease severity and the monitoring of treatment.     

Utilization of nanoparticle labels for signal amplification in ultrasensitive electrochemical affinity biosensors: A review

Nanoparticles with desirable properties not exhibited by the bulk material can be readily synthesized because of rapid technological developments in the fields of materials science and nanotechnology. In particular their highly attractive electrochemical properties and electrocatalytic activity have facilitated achievement of the high level of signal amplification needed for the development of ultrasensitive electrochemical affinity biosensors for the detection of proteins and DNA. This review article explains the basic principles of nanoparticle based electrochemical biosensors, highlights the recent advances in the development of nanoparticle based signal amplification strategies, and provides a critical assessment of the likely drawbacks associated with each strategy. Finally, future perspectives for achieving advanced signal simplification in nanoparticles based biosensors are considered.