| This paper was constituted of review and research reports. In the first part, i.e. review part, Chemical Modified Electrodes (CME), and its development and response mechanism were introduced. Moreover, principles and methods of electrode modifying were reviewed, before the application profile of modified Electrodes being introduced. In the second part, i.e. research reports, MnO2-modified electrode was put forward. This modified Electrode was applied in determining several drugs based on the catalysis of MnO2.Electrode modifying is a process of embedding some molecular or ion polymer which have given properties on electrode surface by means of chemical, physical methods or both of them. As result, the electrode property was changed or improved, and some new function was realized as usual. Some scheduled and selected reaction may come into truth on the modified electrodes. And often, the transmission of electron may enhanced by contrast of non modified Electrodes.The key of preparing a modified electrode lies in the choice of modifying material and method. Scientists keep dedicating themselves in application all kinds of new materials since the birth of CME, hoping that some new properties of those materials can be found, or some judgments can be verified. The same material was applied in analysis different substance can be interpreted by this purpose, too. Once modifying material was determined, a proper modifying method should be decided according to the known properties of that material. There are many kinds of modifying method up to now (such as electrocomposite).Many scholars keep interest in application of CME. As result, this piece of work has been widened range from environmental analysis (such as heavy metal ions, halogen, benzene serials) to food analysis (such as harmful remains of amino Acids and food), immune analysis (such as antigens, antibodies analysis, DNA Hybrid, variation etc.) and drug analysis (such as drugs act on neural system, hormone etc.) etc.The second part, i.e. research reports can be composed of three sections. They are:1. Cyclic voltammetric determine of paracetonl (PAR) by MnO2-modified GCE. In this section, a newly synthesized 13-MnO2 was applied in modifying GCE. At pH 7.2, PAR was determined by this modified electrode. The modified electrode displayed stable response and good sensitivity and repeativity. Compare to non-modified GCE, the oxide potential decreased about 200mV, and current response enhance remarkably. The concentration of PAR was lined with current response from 2.0×10-12 to 4.5×10-9 molL1 (R2=0.9993) with a DL of 6.7×10-13 molL-1 (3σ). Common interferants were checked. In real sample determining, a recovery of 99.0-102.5% was achieved.2. Electrochemiluminescence determine of diethylstilbestrol (DES) by cluster-shaped MnO2-modified GCE. In this section, some factors were investigated, and the optimum condition was decided. Under this condition, DES was determined with the linear range from 3.5×10-11 to 6.5×10-9molL-1, and DL (Detection Limit) was 2.0×10-11 molL-1 (3σ).3. Cyclic voltammetric application of MnO2-modified glassy carbon electrode-- detection of Aciclovir, Naproxen, Perphenazine and Carbamazepiae. This part, newly synthesizedβ-MnO2 was obtained to modify GCE, and this modified GCE was applied in determining those four drugs simultaneously. The modified electrode displayed stable response and good sensitivity and repeativity. Under Cyclic voltammetric condition, the oxide potentials of these four drugs were decreased to some extend comparing to non-modified Electrode. At the same time, current responses were noticeably enhanced. Meanwhile, lower DLs were achieved by contrast to other methods. And possible interferants under physical condition were investigated also. |
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