聚(L)離胺酸-戊二醛-磷鎢酸鹽/矽鉬酸鹽薄膜修飾電極的電化學性質探討

Preparation, Characterization and Electroanalytical Applications of Phosphotungstate/ Silicomolybdate -Incorporated-Glutaraldehyde -Cross-Linked Poly-L-Lysine film Modified Electrodes

潘育慶(Yu-Ching Pan)

指導教授 ： 陳生明

國立臺北科技大學/工程學院/化學工程研究所/碩士(2009年)

摘要

本研究主要分為兩部分來討論，第一部分是使用聚(L)離胺酸-戊二醛-磷鎢酸鹽薄膜修飾玻璃碳電極於0.1M硫酸溶液下對過氧化氫、溴酸根離子、碘酸根離子與過碘酸根離子的電催化反應。於研究中磷鎢酸鹽能成功的製備吸附於聚(L)離氨酸-戊二醛陽離子層薄膜上。且由此修飾電極於只含有0.1 M 硫酸的緩衝溶液中之電流波峰值，可得知在電極表面上發生了快速的電子轉移現象。本研究利用循環伏安法和旋轉碟電極法，觀察比較裸電極與聚(L)離胺酸-戊二醛-磷鎢酸鹽薄膜修飾電極對過氧化氫、溴酸根離子、碘酸根離子與過碘酸根離子的還原反應。此聚(L)離胺酸-戊二醛-磷鎢酸鹽薄膜修飾電極能有效的使過氧化氫發生還原反應且靈敏度為0.02 μAmM-1，但是對於其他的干擾物質，如︰多巴胺(DA)、抗壞血酸(AA)和尿酸(UA)是沒有反應發生的，根據此一特性，可得知聚(L)離胺酸-戊二醛-磷鎢酸鹽薄膜修飾電極於存在有其他干擾物質的狀況下，對過氧化氫的測定仍具有高靈敏度。而其他無機離子，如︰溴酸根離子、碘酸根離子與過碘酸根離子，亦可利用聚(L)離胺酸-戊二醛-磷鎢酸鹽薄膜修飾電極於旋轉碟電極法中進行測定，其所得到的靈敏度分別為3.36，71.66 和 507.43 μAmM-1。
第二部分為使用聚(L)離胺酸-戊二醛-矽鉬酸鹽薄膜修飾電極在0.1M硫酸溶液下對碘酸根離子與過碘酸根離子之還原反應的研究。研究中矽鉬酸鹽能成功的以靜電力吸附製備於聚(L)離胺酸-戊二醛陽離子層薄膜上。由此修飾電極於0.1 M 硫酸緩衝溶液中的電流波峰值，可得知電子轉移速度是非常快速的。本研究中利用循環伏安法和旋轉碟電極法，觀察比較裸電極與聚(L)離胺酸-戊二醛-矽鉬酸鹽薄膜修飾電極對碘酸根離子與過碘酸根離子的電催化反應。而根據碘酸根離子在最佳控制電位為＋200 mV(vs Ag/AgCl)的計時安培法下之催化電流値，可得到一線性濃度範圍為2.5×10-6 到1.2×10-2 M，且計算得到一靈敏度為18.47 μAmM-1；同樣的，過碘酸根離子在–100 mV(vs Ag/AgCl)電位下，亦具有一線性濃度範圍為5×10-6 到1.43×10-4 M，且靈敏度為1017.7 μAmM-1。

關鍵字

聚(L)離胺酸-戊二醛-矽鉬酸鹽/磷鎢酸鹽 ； 聚(L)離胺酸薄膜 ； 薄膜修飾電極 ； 電催化反應 ； 過氧化氫 ； 溴酸根離子 ； 碘酸根離子 ； 過碘酸根離子 ； 選擇性偵測

並列摘要

Part I ： The present work describes preparation and characterization of
phosphotungtate-doped-glutaraldehyde-cross-linked poly-L-lysine (PLL-GA-PW) film
modified glassy carbon electrode and its electrocatalytic behavior towards reduction of
hyhrogen peroxide (H2O2), bromate (BrO3
-) iodate (IO3
-), and periodate (IO4
-) in 0.1 M
H2SO4. The modified electrode has been successfully prepared by means of
electrostatically trapping the phosphotungtate mediator in the cationic film of
glutaraldehyde-cross-linked poly-L-lysine. The dependence of peak current of modified
electrode in pure supporting indicates that the charge transfer in the film is fast and
iv
resembles that of surface confined species. Cyclic voltammetry was used to investigate
the electrocatalytic reduction of H2O2 and BrO3
-, IO3
- and IO4
-, and compared with their
reduction at bare and undoped PLL-GA film coated electrodes. The analytical
determination of H2O2 has been carried out in stirred solution at an optimized potential
with a sensitivity of 0.02 μA mM-1. Interestingly, PLL-GA-PW modified electrode
facilitated the reduction of H2O2, and not responded to potential interferents such as
dopamine, ascorbic acid and uric acid. This unique feature of PLL-GA-PW modified
electrode allowed for the development of a highly selective method for the
determination of H2O2 in the presence of interferents. Similarly, the inorganic ions were
also determined using PLL-GA-PW modified electrode in stirred solution with the
sensitivity of 3.36, 71.66 and 507.43 μA mM-1, respectively for bromate, iodate and
periodate.
Part II： The present work describes reduction of iodate (IO3
-), and periodates (IO4
-)
at silicomolybdate-doped-glutaraldehyde-cross-linked poly-L-lysine (PLL-GA-SiMo)
film modified glassy carbon electrode in 0.1M H2SO4. In our previous investigation, we
were able to prepare the PLL-GA-SiMo modified electrode successfully by means of
electrostatically trapping the silicomolybdate mediator in the cationic film of
glutaraldehyde-cross-linked poly-L-lysine, and the voltammetric investigation in pure
supporting indicated that the charge transfer process was fast. Here, we used
PLL-GA-SiMo film electrodes for their further application in electrocatalysis. The
electrocatalytic reduction of IO3
- and IO4
- were studied at PLL-GA-SiMo film
electrodes and compared with bare and undoped PLL-GA film coated electrodes. Finally,
the analytical application of PLL-GA-SiMo film modified electrode is demonstrated as
amperometric sensor for both inorganic ions in stirred solution. At an optimized
potential (+200 mV (vs Ag/AgCl)), the PLL-GA-SiMo film electrode exhibits a wide
v
linear concentration range between 2.5×10-6 to 1.1×10-2 M with a sensitivity of 18.47
μA mM-1 for iodate determination at while the linear range, sensitivity of periodate at
-100 mV (vs Ag/AgCl) were 5×10-6 to 1.43×10-4 M and 1014.7 μA mM-1, respectively.

並列關鍵字

Phosphotungtate-doped-glutaraldehyde-cross-linked poly-L-lysine film ； Silicomolybdate ； Modified electrode ； Electrocatalysis ； Hydrogen peroxide ； Bromate ； Iodate ； Periodate ； Selective detection

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