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61.
Easy deposition of Ag onto polystyrene beads for developing surface-enhanced-Raman-scattering-based molecular sensors 总被引:1,自引:0,他引:1
We describe a very simple electroless plating method that can be used to prepare Ag-coated polystyrene beads. Robust Ag nanostructures are reproducibly fabricated by soaking polystyrene beads in ethanolic solutions of AgNO(3) and butylamine. When the molar ratio of butylamine to AgNO(3) is far below 1.0, distinct nanosized Ag particles are formed on the polystyrene beads, but by increasing the amount of butylamine, network-like Ag nanostructures are formed that possess very broad UV/vis absorption characteristics extending from the near-UV to near-infrared regions. In conformity with the UV/vis absorption characteristics, the Ag-deposited polystyrene beads were highly efficient surface-enhanced Raman scattering (SERS) substrates, with an enhancement factor estimated using 4-aminobenzenethiol (4-ABT) as a model adsorbate to be larger than 1.1x10(6). On the basis of the nature of the SERS peaks of 4-ABT, those Ag-deposited polystyrene beads were confirmed, after attaching biotin groups over 4-ABT, to selectively recognize streptavidin molecules down to concentrations of 10(-11) g mL(-1) (i.e., approximately 0.2 pM). Since a number of different molecules can be used as SERS-marker molecules (such as 4-ABT), multiple bioassays are readily accomplished via SERS after attaching appropriate host or guest molecules onto them. 相似文献
62.
A commercially-available sulfonphthalein derivative was demonstrated to be a chemodosimeter for Fe2+ and its sensing behavior was further investigated by UV-vis spectroscopy in aqueous media under the optimum conditions. In the presence of chlorophenol red (CPR) and H2O2, the absorption maximum at 435 nm decreased upon addition of Fe2+, resulting in a significant color change of the CPR solution from yellow to colorless. The chemosensor system did not show significant responses to a series of other metal ions including Al3+, Zn2+, Cd2+, Hg2+, Mn2+, Co2+, Fe3+, Ni2+, Cu2+, La3+, Ce4+, Th4+, Pd2+, Pb2+, Sb3+, Cr3+, Au3+, Ag+, Nd3+, Sm3+, alkali and alkaline earth metal cations, allowing for highly selective naked-eye detection of Fe2+. Quantitative analysis was carried out kinetically for practicable the Fe2+ assay when either fixed time method or the initial rate method was applied. When the detecting time was set, the decrease of absorbance signal was linear with Fe2+ concentration in the range of 0 to 7.50 × 10?5 mol L?1 and the regression equation was ΔA = 0.00759 + 0.00593C Fe with a correlation coefficient r = 0.9953. The chemodosimetric system has employed an irreversible Fenton reagent-promoted oxidation of the CPR free chromophore and the hydroxyl radicals were generated in the presence of both Fe2+ and hydrogen peroxide. The mechanistic interpretation of the signaling process was partially confirmed by the radical scavenging experiment and the FT-IR analysis of the intermediates formed at different reaction periods. 相似文献
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64.
以无水乙醇为溶剂,将Cu、Zn和Al的硝酸盐并流共沉淀在HZSM-5分子筛的悬浮溶液中,一步合成CuO-ZnO-Al2O3/HZSM-5双功能催化剂.研究了沉淀剂的种类、加入顺序和加入量对催化剂活性的影响.结果表明,以适量的草酸作沉淀剂,采用悬浮液并流共沉淀法制备的双功能催化剂,对CO2加氢直接合成二甲醚有较高的催化性能:在固定床反应器中,温度为270℃,压力为3.0 MPa,空速为4 800 h-1的反应条件下,CO2的单程转化率达到28.7%,二甲醚的选择性达到53.2%.BET、XRD、TPR、TPD和N2O滴定等对催化剂结构表征结果表明,双功能复合催化剂CuO-ZnO-Al2O3/HZSM-5的结构影响CO2加氢合成二甲醚的催化性能. 相似文献
65.
Yupeng Wu Yangchun Tao Kuan Cai Siwei Liu Yi Zhang Zhenguo Chi Jiarui Xu Yen Wei 《中国化学》2015,33(12):1338-1346
Two triblock polymers, tetraaniline‐block‐poly(N‐isopropyl acrylamide)‐block‐poly(hydroxyethyl acrylate) (TA‐b‐PNIPAM‐b‐PHEA) and TA‐b‐PHEA‐b‐PNIPAM, were synthesized with unambiguous structure by a two step method. The difference of these two diblock polymers is the connection order of carboxyl group to block, e.g., carboxyl group to PNIPAM block for PNIPAM‐b‐PHEA and to PHEA block for PHEA‐b‐PNIPAM. Secondly, block tetraaniline was linked to the diblock polymer through amidation to yield the corresponding triblock copolymer. Both of them have almost the identical chemical compositions. The only difference is the connection order of each block in the triblock polymers. When they were self‐assembled at 45°C in a suitable solution, both of their aggregates have spherical shape with slight defects on their surface with the average diameter of about 400 nm. However, when their aggregate dispersion was cooled down to 20°C, only TA‐b‐PHEA‐b‐PNIPAM's morphology changed, forming worm‐like aggregates with the diameter of about 100–200 nm transformed from spherical aggregates. Both amphiphilic property and position of each block in this triblock copolymer are very essential for this morphology transformation. Since the worm‐like aggregates presented here by our group have hollow structure inside, its controlled release properties for doxorubicin were evaluated. Drug release experiment indicated that along with the temperature changes, the rearrangement of the intermediate layer structure caused morphology change in aggregate, thus accelerating the speed of drug release. 相似文献
66.
The effects of group-delay difference in an active nonlinear long-period fiber grating (LPFG) made in an erbium-doped amplifying fiber (EDF) are investigated by proposing a general model that include the effects of detuning, group-delay difference, gain saturation, gain bandwidth and Kerr nonlinearity. In particular, we observe a new feature caused by the interaction between the group-delay difference and the gain bandwidth: the pulse breakup effect due to the group-delay difference can be suppressed by the finite bandwidth of the linear gain. 相似文献
67.
Kin ChinKazuo Eda Noriyuki Sotani M.Stanley Whittingham 《Journal of solid state chemistry》2002,164(1):81-87
Blue potassium molybdenum bronze, K0.28MoO3, was prepared by hydrothermal heating hydrogen molybdenum bronze in KCl solution at 431 K. Hydrated molybdenum bronze was found formed as an intermediate during the conversion from hydrogen molybdenum bronze to blue bronze. The hydrothermal method proved itself an easy and effective for synthesis of mixed-valence compounds. 相似文献
68.
0IntroductionPhenanthrolinederivativescontainingaminegroupshavebothsoftandhardsitesandaregooddonorsformetalions.1,10鄄phenanthrolineanditsderivativeshavebeenextensivelyusedasligandsinbothanalyticalandpreparativecoordinationchemis鄄try[1].Mostoftheseworksh… 相似文献
69.
70.
Jian‐Ging Chen Ken‐Yen Liu Chia‐Yuan Chen Chia‐Yu Lin Kuan‐Chieh Huang Yi‐Hsuan Lai Chun‐Guey Wu King‐Fu Lin Kuo‐Chuan Ho 《Journal of polymer science. Part A, Polymer chemistry》2010,48(22):4950-4957
This study reports the characteristics of gel‐type dye‐sensitized solar cells (DSSCs), fabricated with gel‐type electrolyte containing poly‐1,1′‐(methylenedi‐4,1‐phenylene)bismaleimide (PBMI), or poly‐1,1′‐(3,3′‐dimethyl‐1,1′‐biphenyl‐4,4′‐diyl)bismaleimide (PDBBMI), or poly‐N,N′‐(4‐methyl‐1,3‐phenylene)bismaleimide (PMPBMI), prepared by in situ polymerization of the corresponding monomer without an initiator at 30 °C. Incorporating 0.3 wt % content of exfoliated alkyl‐modified nanomica (EAMNM) into PBMI‐gelled electrolyte leads to higher short‐circuit current density (Jsc = 17.14 mA cm?2) and efficiency (η = 7.02%) than that of neat PBMI‐gel electrolyte (Jsc = 15.32 mA cm?2, η = 6.41%). Incorporating 0.3 wt % EAMNM into PBMI‐gelled electrolyte results in remarkably stable device performance under continuous light soaking under one sun (100 mW cm?2) at 55 °C. The efficiency of DSSCs based on PBMI/0.3 wt % EAMNM‐gelled electrolyte drops by only 1.7% (η = 6.93%) after 500 h of continuous light soaking. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献