Entrapment of glucose oxidase in non-porous poly(vinyl chloride)
Entrapment of glucose oxidase in non-porous poly(vinyl chloride)
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DOI：
10.1016/s0003-2670(02)00246-5
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发表时间：
2002-06-12
影响因子：
6.2
通讯作者：
Vadgama, P
中科院分区：
文献类型：
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作者：
Reddy, SM;Vadgama, P
我们使用溶剂浇铸技术将葡萄糖氧化酶（GOD）固定在未增塑和增塑的聚氯乙烯（PVC）基质中。增塑剂;研究的是阳离子表面活性剂三辛基甲基氯化铵（Aliquat 336 s）、阴离子表面活性剂磷酸氢二（2-乙基己基）酯（BEP）和脂质肉豆蔻酸异丙酯（IPM）。采用电流电极法检测酶膜的活性。酶膜电极响应的变化是合理的膜选择透过性的基础上。Aliquat和IPM改性的PVC膜由于更好的保留和随后的H2 O2信号物质的浓缩而产生放大的信号。实际上，损失到本体溶液中的更少。在BEP改性的膜的情况下，虽然在高达50 mM的响应中存在线性阶跃变化，但在更高的浓度下，响应没有达到稳态;它们的特征是响应向上漂移0.050 nA/分钟。这种特征被认为是由于葡萄糖酸的积累导致膜微环境的pH值降低以及相邻BEP之间的氢键合分子。在这种情况下，我们以前已经表明，膜对亲水性物质的渗透性减弱，并初步认为，由于H_2O_2在电极侧的积累，通过酸化膜进入本体溶液的渗透较少，因此向上漂移。（但没有包埋酶）作为经典双膜葡萄糖酶电极构造的外膜。在后一种情况下，使用戊二醛使酶在膜之间化学交联。(C)2002 Elsevier Science B. V.保留所有权利。
We have used solvent casting techniques to immobilise glucose oxidase (GOD) within unplasticised and plasticised poly(vinyl chloride) (PVC) matrices. The plasticisers; studied were the cationic surfactant, tricaprylmethylammonium chloride (Aliquat 336s), the anionic surfactant bis(2-ethylhexyl) hydrogenphosphate (BEP) and the lipid, isopropylmyristate (IPM). The activity of the enzyme-membrane was tested by amperometric electrode. Changes in enzyme-membrane electrode response are rationalised on the basis of membrane permselective properties. The Aliquat and IPM modified PVC membranes gave amplified signals due to better retention and subsequent concentration of the H2O2 signal species. Effectively, less was being lost to the bulk solution. In the case of the BEP-modified membrane, while there was a linear step change in response up to 50 mM, at higher concentrations, responses did not reach steady-state; they were characterised by an upward drift in response of 0.050 nA/min. This characteristic is thought to be due to a build up of gluconic acid resulting in a pH reduction in the membrane microenvironment and hydrogen bonding between neighbouring BEP molecules. Under these conditions, we have previously shown that the membrane permeability to hydrophilic species is attenuated and it is tentatively suggested that the upward drift due to the build up of H2O2 on the electrode side with less permeating through the acidified membrane into bulk solution.The results were compared against using variously plasticised PVC (but no enzyme entrapped) as an outer membrane of a classical dual-membrane glucose enzyme electrode construct. In the latter case, the enzyme was chemically crosslinked between the membranes using glutaraldehyde. (C) 2002 Elsevier Science B.V. All rights reserved.