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A new fabrication process for a microchip electrophoresis device integrated with a three-electrode electrochemical detector 总被引:1,自引:0,他引:1
We report here a novel and simple process for the fabrication of a poly(methyl methacrylate) (PMMA)-based microchip electrophoresis device, integrated with a screen-printed three-electrode electrochemical detector that does not require a replicate mold. In this approach, a photoresist layer constitutes both an adhesion layer and side walls of 50 mum wide and 50 mum tall microfluidic channels on a screen-printed three-electrode PMMA substrate. Openings were drilled for buffer reservoirs on an additional piece of PMMA, then the final device was bonded in a PMMA/photoresist/PMMA sandwich configuration. This process is inexpensive, less time-consuming, and simpler compared with traditional fabrication methods. The combination of this PMMA-based microchip fabrication together with screen-printed electrode technology holds great promise for the mass production of a single-use micrototal analytical system. Successful determination of uric acid and L-ascorbic acid with the presented system validates its utility. In combination with a suitable electrochemical detector, this device holds much promise for the determination of other analytes in various biological samples for medical and clinical diagnosis. 相似文献
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ZEN Jyh-Myng 《高等学校化学研究》2001,17(3)
We report here the development of chemical sensors based on screen-printed technology in our research group to solve major analytical problems in environmental and clinical aspects. The purpose of the research is aimed at the enhancement of selectivity and sensitivity for analysis and monitoring of pollutants and analytes using novel chenically modified screen-printed electrodes. For example, an enzyme reactor coupled with a copper-plated screen-printed carbon electrode (CuSPE) was developed for glucose sensing. The electrocatalytic reduction of enzymatically produced H2O2 at the CuSPE was determined by flow injection analysis (FIA) in pH 7.4 PBS. The proposed method was applied to determine glucose content in fruit juice and clinical sample and satisfactory results with good recoveries were obtained. A thoroughly kinetics and mechanism study was also done for those systems that are verified in analytical applications. 相似文献
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A flow injection analysis coupled with electrochemical detection at an activated barrel plating nickel electrode (Ni-BPE) was developed as a sensitive, simple, and low-cost formaldehyde sensor. The mechanism of Ni-BPE toward the electrocatalytic oxidation of formaldehyde in alkaline medium at ambient temperature was proposed to be based on the electrocatalytic oxidation of formaldehyde by Ni(III)O(OH) species. Under the optimized conditions (flow rate = 1.2 mL/min; detection potential = +0.5 V versus Ag/AgCl), a good linearity in the window of 0.037 to 10 microg/mL formaldehyde was observed, and the LOD of 0.23 microg/L was calculated. The RSDs of intraday (n = 10) and interday (n = 6) replicate measurements of 0.185-5 microg/mL formaldehyde ranged from 1.45 to 3.60%, indicating good reproducibility of the proposed method. The proposed method was successfully applied to the determination of formaldehyde in commercial nail polish samples and a drinking water sample. 相似文献
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Jyh-Myng Zen Fu-Shien Hsu Nai-Yuen Chi Sen-Yuan Huang Mu-Jye Chung 《Analytica chimica acta》1995,310(3):407-417
The effect of various organic compounds on the Nafion/chelating agent mercury film electrodes (NCAMFEs) in square-wave anodic-stripping voltammetry (SWASV) is explored. Two chelating agents used to prepare the NCAMFEs are dimethylglyoxime and 2,2'-bipyridyl. Triton X-100, sodium dodecyl sulfate, albumin, gelatin, starch, camphor, and humic acid are used as model organic compounds, while cadmium, lead, and copper are used as test metal ions. The NCAMFEs are considerably more resistant to organic interferences than the Nafion-coated mercury film electrode. The implications of these interferences for the reliability and feasibility of stripping measurements using the NCAMFEs in real samples are discussed. Results presented for untreated urine and natural water samples demonstrate the analytical utility of the NCAMFEs in SWASV. 相似文献
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快速溶剂萃取一气相色谱法测定土壤中多氯联苯Aroclor系列 总被引:1,自引:0,他引:1
建立了快速溶剂萃取、浓硫酸净化、气相色谱法测定土壤中多氯联苯Aroclor系列的方法.方法线性良好、灵敏度高、回收率在70%~110%之间、相对标准偏差RSD小于17%,并用于有证的标准土壤样品及环境实样的分析,结果满意. 相似文献
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Cheng-Teng Hsu Hsieh-Hsun Chung Huieh-Jing Lyuu Dong-Mung Tsai Annamalai Senthil Kumar Jyh-Myng Zen 《Analytical sciences》2006,22(1):35-38
An electrochemical cell coupled with disposable screen-printed electrodes (SPEs) that is specifically designed for use in flow injection analysis (FIA) is described in this study. The cell is made of foldable polyoxymethylene (acetal) thick platelets with the bottom portion consisting of a cavity track to drag the SPEs in position and the top portion having predrilled T-like holes to arrange the Ag/AgCl reference electrode and stainless steel inlet & outlet. An "O ring" is suitably fixed on the top of the working electrode to form a thin-layer space where the electrochemical reaction can take place. Hydrodynamic characterization was validated by using a benchmark hexacyanoferrate redox couple. The results of practical analysis of glucose in human plasma clearly demonstrate the characteristics and applicability of the proposed wall-jet electrochemical cell in FIA. 相似文献
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Tahir SAVRAN Abdurrahman KARAG
Z ükriye Nihan KARUK ELMAS Duygu AYDIN Furkan
ZEN Kenan KORAN Fatma Nur ARSLAN Ahmet Orhan G
RGÜLÜ brahim YILMAZ 《Turkish Journal of Chemistry》2020,44(4):1148
A fluorogenic probe based on a coumarin-derivative for Cu2+ sensing in CH3CN/H2O media (v/v, 95/5, 5.0 μM) was developed and applied in real samples. 3-(4-chlorophenyl)-6,7-dihydroxy-coumarin (MCPC) probe was obtained by synthetic methodologies and identified by spectral techniques. The probe MCPC showed remarkable changes with a “turn-off” fluorogenic sensing approach for the monitoring of Cu2+ at 456 nm under an excitation wavelength of 366 nm. The response time of the probe MCPC was founded as only 1 min. The detection limit of the probe MCPC was recorded to be 1.47 nM. The binding constant and possible stoichiometric ratio (1:1) values were determined by Benesi-Hildebrand and Job’s plot systems, respectively. The mechanism of the probe MCPC with Cu2+ was further confirmed by ESI-MS and FT-IR analyses, as well as supported by theoretical calculations. Furthermore, the probe MCPC was successfully employed for the practical applications to sense Cu2+ in different herbal and black tea samples. The proposed sensing method was also verified by ICP-OES method. 相似文献
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A preanodized screen-printed carbon electrode is used for the determination of magnesium ascorbyl phosphate in cosmetic bleaching products. The preanodization process exhibits a marked enhancement of the current response of magnesium ascorbyl phosphate at the screen-printed carbon electrode. The linear range is up to 240 (correlation coefficient = 0.999) in pH 2.0 citrate buffer with a detection limit (S/N = 3) of 0.33 μM. The electrode has the advantages of low cost and easy of handling and can be either disposable or reused since the renewal gives a good reproducible surface. Quantitative analysis was performed by the standard addition method for magnesium ascorbyl phosphate content in cosmetic products. 相似文献