Enhanced Stability of Enzyme Immobilized in Rationally Designed Amphiphilic Aerogel and Its Application for Sensitive Glucose Detection
Enhanced Stability of Enzyme Immobilized in Rationally Designed Amphiphilic Aerogel and Its Application for Sensitive Glucose Detection
复制标题
合理设计的两亲性气凝胶中酶固定化的增强稳定性及其在灵敏葡萄糖检测中的应用
DOI：
10.1021/acs.analchem.9b05858
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发表时间：
2020
影响因子：
7.4
通讯作者：
Wang Erkang
中科院分区：
文献类型：
--
作者：
Ma Chong-Bo;Zhang Yu;Liu Qiong;Du Yan;Wang Erkang
天然酶复合物是由多个亚基组成的复合体，它们在生物体系中具有催化级联反应的能力，但与自由漂浮的天然酶一样，在高温等恶劣环境下会发生失活。在这项研究中，一个目的驱动的设计的两亲性气凝胶作为酶的固定化底物，形成多酶复合物（MEC）的证明。该气凝胶仅由单一聚合物聚乙烯醇（PVA）以及表面调节剂马来酸（MA）合成，其掺入调谐表面润湿性。两亲性气凝胶的使用有利于多酶的固定化，保持酶的构象，并使酶在高温下保持稳定。作为一个典型的例子，葡萄糖氧化酶和氯化血红素牢固地共固定在气凝胶基质中，并积极催化（i）葡萄糖到葡萄糖酸和（ii）3，3，5，5-四甲基联苯胺（TMB）到其氧化态的级联反应。酶在高温（70-100 °C）下能抵抗降解，这可以通过活性下降速率逐渐减缓来证明。利用TMB的显色反应，建立了气凝胶-酶复合物葡萄糖传感器，用于全血和汗液中葡萄糖的检测，结果可靠，回收率满意。改性后的气凝胶还能承受多次物理变形，同时保持良好的吸附能力和催化性能。酶负载气凝胶模型可能有助于基于其他分析物组成传感器。
Natural enzyme complex with the subunits cooperating with each other could catalyze cascade reactions in biological system but, just like the limitation of free-floating natural enzymes, usually suffer from deactivation in harsh environment such as high temperature. In this study, a purpose-driven design of amphiphilic aerogel working as the enzymes-immobilization substrate to form the multienzyme complex (MEC) was demonstrated. The aerogel was synthesized only by a single polymer poly(vinyl alcohol) (PVA) as well as a surface modulator maleic acid (MA), the incorporation of which tunes the surface wettability. The usage of the amphiphilic aerogel may do favor for multienzyme immobilization, conserving the enzyme conformation as well as stabilizing the enzymes in high temperature. As a typical example, glucose oxidase and hemin were firmly coimmobilized in the aerogel matrix and actively catalyze the cascade reactions of (i) glucose to gluconic acid and (ii) 3,3,5,5-tetramethylbenzidine (TMB) to its oxidized state. The enzymes could resist the degradation under high temperature (70–100 °C) which is witnessed by the rate of decrease in activity was progressively slackened. Taking the advantage of the chromogenic reaction of TMB, a glucose sensor based on aerogel-enzyme composite for glucose detection in whole blood and sweat was established, exhibiting reliable results and satisfactory recovery. The modified aerogel could also withstand multiple physical deformation meantime maintaining good adsorption capacity as well as catalytic performance. The enzymes-loading aerogel model may hopefully contribute to composing sensors based on other analytes.