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951.
《Electroanalysis》2003,15(9):787-796
The use of [Cu(bipy)2]Cl2?6H2O as a biomimetic catalyst in the construction of an amperometric sensor for dopamine determination is reported. The sensor was prepared modifying a glassy carbon electrode with a Nafion membrane doped with [Cu(bipy)2]Cl2?6H2O complex. The sensor presented a higher response in 0.25 mol L?1 phosphate buffer solution (pH 7.0), with an applied potential of ?50 mV (vs. SCE). In the optimized operational conditions, a linear response range between 35 and 240 μmol L?1, with a sensitivity of 2.02±0.07 nA l μmoL?1 cm?2 and detection limit of 8.0 μmol L?1 were typically observed for the sensor. The response time presented for this sensor was 0.5 s, presenting the same response for at least 40 successive measurements, with good repeatability (3.0%) expressed as relative standard deviation for n=6. The difference of the response between four sensor preparations was 4%. A detailed investigation about the sensor response for other sixteen phenolic compounds and interfering species were carried out. The sensor was applied in the determination of dopamine in pharmaceutical preparation with success. 相似文献
952.
953.
一种新型光电式液位传感器 总被引:2,自引:0,他引:2
本文介绍一种新型光电式液位传感器的设计原理、光路的理论分析。该传感器具有液位测量准确、反应灵敏、防暴、使用寿命长等优点,是一种有很大实用价值的新型液位传感器。 相似文献
954.
955.
Detection and analysis of paraffin oil adulteration in coconut oil using fiber optic long period grating sensor 总被引:1,自引:0,他引:1
A fiber optic sensing system for the detection of adulteration of coconut oil by paraffin oil is experimentally demonstrated. The sensing mechanism is based on the sensitive dependence of the resonance peaks of a long period grating (LPG) on the changes of the refractive index of the environmental medium surrounding the cladding surface of the grating. The wavelength shift of the attenuation bands of the LPG was measured with the sensor immersed in a mixture of paraffin oil and pure coconut oil in different proportions. Detection limit of adulteration was found to be 3% for coconut oil-paraffin oil binary mixture. 相似文献
956.
AbstractThis article presents the theoretical and experimental investigation of the response of long-period gratings as a refractive index sensor. Cladding modes are calculated, and results are compared with Optigrating 4.2.2 (Optiwave Systems Inc., Ottawa, Canada). The response has been checked for refractive indices ranging from 1 to 1.458. Theoretically simulated results are in accordance with the experimental results. It was found that the software package calculated values correctly up to the seventh decimal point. The ambient refractive index response of a long-period grating over a much wider index range has been modeled for values both less and more than the cladding refractive index. 相似文献
957.
A nonenzymatic amperometric sensor for sensitive and selective detection of glucose has been constructed by using highly dispersed Pt nanoparticles supported onto mesoporous carbons (MCs). The Pt nanoparticles/mesoporous carbons (Pt/MCs) composites modified electrode displayed high electrocatalytic activity towards the oxidation of glucose. At an applied potential of 0.1 V, the Pt/MCs electrode has a linear dependence (R=0.996) in the glucose concentration up to 7.5 mM with a sensitivity of 8.52 mA M?1 cm?2. The Pt/MCs electrode has also shown highly resistant toward poisoning by chloride ions and without interference from the oxidation of common interfering species. 相似文献
958.
Jerzy Paczkowski D. C. Neckers 《Journal of polymer science. Part A, Polymer chemistry》1993,31(3):841-846
Several new fluorescence probes useful for following photopolymerization have been characterized. Among these are probes which can be used in rapidly gelling monomer mixtures and for photochemical polymerization initiated by very high laser powers. Systems which can be used with polyolacrylates and either with visible initiators or with UV initiators are reported. © 1993 John Wiley & Sons, Inc. 相似文献
959.
《Tetrahedron letters》2014,55(51):7094-7098
A new thiacalix[4]arene based fluorescent chemosensor thiacalix[4]arene-N-(quinolin-8-yl)acetamide (TCAN8QA) has been synthesized. TCAN8QA has been found to exhibit highly selective behavior for F− ions among all other anions, that is, Cl−, Br−, I−, PO4−3, OH−, H2PO4−, and CH3COO− in the absorption spectra as well as in the emission spectra. Red shift and quenching in emission spectra constituting the signature for fluoride detection are due to photoinduced charge transfer (PCT) which can be attributed to deprotonation of acidic NH proton in the presence of fluoride ions. 相似文献
960.
设计合成了一系列结构相似的共轭主链含5%苯并噻二唑结构单元及侧链带胺类金属离子螯合基团的阴离子型水溶性共轭聚合物PFA, PFBTA和PFBTNA, 并对它们在不同极性溶剂中的光物理性质进行了研究. 利用分子主链含适量苯并噻二唑共聚单元的聚芴衍生物聚集态不同荧光光谱及颜色发生显著变化这一特性, 研究了这一系列水溶性聚芴衍生物在水/甲醇(9/1)溶液中对金属离子的荧光响应过程. 结果表明, 金属离子不仅能通过能量及电荷转移猝灭聚合物荧光, 还可以通过静电相互作用力使聚合物聚集态发生改变, 进而影响聚合物的光学性质. 同时分子链上引入金属离子螯合基团能够显著提高体系的检测灵敏度, 聚合物PFBTA和PFBTNA可以特异性识别Cu2+离子, 并且可做为其它金属离子的广谱型比色法检测材料. 相似文献