Au@Ag Heterogeneous Nanorods as Nanozyme Interfaces with Peroxidase-Like Activity and Their Application for One-Pot Analysis of Glucose at Nearly Neutral pH

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• 作者：Lei Han ; Cuncheng Li ; Tao Zhang ; Qiaolin Lang ; Aihua Liu
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：July 8, 2015
• 年：2015
• 卷：7
• 期：26
• 页码：14463-14470
• 全文大小：412K
• ISSN：1944-8252

文摘

As substitutes for natural peroxidases, most nanomaterial-based enzyme mimetics (nanozymes) have unique properties such as high stability, low-cost, large surface area, and high catalytic activity. However, they usually work in acidic conditions and thus impede their real applications. In this work, by modulating the nanostructure, composition, and surface property of the bimetallic materials, the positively charged poly(diallyldimethylammonium)-stabilized Au@Ag heterogeneous nanorods (NRs) were developed as synergistic peroxidase-like interfaces, which exhibited high activity over a wide pH range (pH 4.0鈥?.5) using 2,2鈥?azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) as the chromogenic substrate. At pH 6.5, the peroxidase-like activity for the Au@Ag heterogeneous NRs was stable and optimal within 20鈥?0 掳C. Moreover, the Au@Ag heterogeneous NRs showed excellent temperature stability and long-term storage stability. Given these characters, the detection of H₂O₂ at pH 6.5 was proposed on the basis of the Au@Ag heterogeneous NRs catalyzing the colorimetric reaction of H₂O₂ and ABTS, where the oxidized ABTS showed a typical absorption peak at 414 nm. The absorbance at 414 nm was linear with H₂O₂ concentration from 0.01 to 10 mM. Further, considering that Au@Ag heterogeneous NRs and glucose oxidase (GOx) have similar optimal pH for catalytic activities, a novel one-pot method for the detection of glucose was developed by the coupled catalytic reaction using GOx, Au@Ag heterogeneous NRs, and ABTS at nearly neutral pH (pH 6.5) and 37 掳C. This proposed method had simple and rapid processes, wide linear range (0.05鈥?0 mM), and reliability for the successful analysis of real samples. On the basis of these attractive and unique characteristics, Au@Ag heterogeneous NRs can become promising substitutes for peroxidase in analytical chemistry and environmental science.