Synthesis and electrocatalytic behavior of Co3O4 toward reduction of hydrogen peroxide and its application in development of uric acid biosensor

機構典藏 > College of Sciences > Graduate Institute & Department of Chemistry > Thesis > Item 987654321/102147

Please use this identifier to cite or link to this item: https://tkuir.lib.tku.edu.tw/dspace/handle/987654321/102147

Title:	Synthesis and electrocatalytic behavior of Co3O4 toward reduction of hydrogen peroxide and its application in development of uric acid biosensor
Other Titles:	四氧化三鈷之合成與尿酸生化感測器之應用
Authors:	吳依靜;Wu, Yi-Jing
Contributors:	淡江大學化學學系碩士班林孟山;Lin, Meng-Shan
Keywords:	尿酸;尿酸酶;四氧化三鈷;生化感測器;uric acid;Uricase;Co3O4;Biosensor
Date:	2014
Issue Date:	2015-05-04 09:48:34 (UTC+8)
Abstract:	本實驗利用四氧化三鈷(Co3O4)在鹼性下催化過氧化氫還原的特性研究，利用交聯法將對尿酸具有專一性辨識力的尿酸酶(Uricase, EC 1.7.3.3)固定於四氧化三鈷的修飾旋轉電極上，發展成尿酸電化學生化感測器。分別利用高解析度 X光繞射儀(HRXRD)與場發式掃描電子顯微鏡(FE-SEM)，針對由水熱法所製備的鈷氧化物定性與表面分析的量測，結果顯示自製鈷氧化物為四氧化三鈷且為矩形奈米片堆積結構。而此尿酸生化感測器之最佳化製備條件為70% (w/w%) Co3O4修飾於RGDE電極表面，置於80℃烘箱1小時乾燥，隨後在電極上修飾5 μL 0.5%小牛血清蛋白，靜置4℃乾燥後再加入5 μL 0.1%戊二醛靜置4℃乾燥，最後再滴上0.5 units尿酸酶靜置4℃乾燥即完成電極的製備。而該生物傳感器最佳化偵測條件為0.05 M pH 9.5 Clark & Lubs 緩衝液，偵測電位為0.05V (vs. Ag/AgCl)，電極旋轉速度為400rpm環境下進行尿酸偵測。根據上述操作條件，此感測器分析特性如下:線性範圍可達2 μM - 102 μM(R=0.999)，靈敏度為18.24 μA/mM，偵測極限為0.6μM，在精確度(precision)方面連續重複偵測25 μM尿酸20次操作下，所得到的標準偏差(RSD)為1.38%，反應時間(t90%/10%)為27.34秒。根據干擾物測量結果顯示，在此電位下常見的干擾物，例如acetaminophen、creatin以及dopamine不會有明顯干擾外，其他的干擾比率界於-556.56 % ~5.8% 之間。而針對抗壞血酸(Ascorbic acid)的干擾，若在偵測前1小時先加入抗壞血酸酶(Ascorbate oxidase)進行預處理，即可避免抗壞血酸之干擾。最後，此感測器在不使用時保存於4℃冰箱緩衝溶液中，其活性維持至少83 天不變，結果顯示該電極具有良好的穩定性，其83 天間的精確度為4.12 %。 In current study, a cobalt oxide based uric acid biosensor is fabricated through a drop coating of glutaraldehyde, and uricase onto a BSA coated Co3O4 based rotating disc graphite electrode (RGDE). Uric acid is measured via an uricase based Co3O4 modified biosensor cathodicly. The amperometric signal of this sensor is measured based on the uricase converts uric acid into hydrogen peroxide and reduces by Co3O4. The homemade cobalt oxide fabricated by hydrothermal synthesis is better than the commercial one. Qualitative analysis and morphology of cobalt oxide was characterized by High resolution X-ray diffractmeter (HRXRD) and scanning electron microscopic (SEM). The results show that homemade cobalt oxide is Co3O4 and exhibits rectangular sheets with pore and piled the nanosheets of each other. The uric acid biosensor was simply fabricated with mixing carbon ink and 70% Co3O4 then placed on RDGE and dried in the oven at 80℃ for an hour. Followed drop coated 5 μL 0.5 % BSA, 5 μL 0.1% glutaraldehyde, and 5 μL 0.5 units uricase onto electrode till dried in 4℃ refrigerator. The biosensor showed optimum conditions for the analysis of uric acid are in 0.05 M pH 9.5 Clark & Lubs buffer, when applied at 0.05 V (vs. Ag/AgCl) with rotating rate of 400rpm. The linear range of this scheme covers from 2 μM to 102 μM (R=0.999), with sensitivity is 18.24 μA/mM and a detection limit of 0.6 μM. The relative standard deviation (RSD) for 20 times successive measurement of 25 μM UA is 1.38%, and the response time (t90%/10%) is 27.34 s. These metabolites have interference except acetaminophen, creatine, and dopamine. Others ratio of interference were between -556.56 % and 5.8%. Among these metabolites, ascorbic acid has -556.56 % interference. Therefore, the removal of AA interference could be eliminated by pretreatment of 10 units ascorbate oxidase with sample for one hour in advance. This sensor has good stability during 83 days study with 4.12% of RSD.
Appears in Collections:	[Graduate Institute & Department of Chemistry] Thesis

Files in This Item:

File	Size	Format
index.html	0Kb	HTML	208	View/Open

Loading...