Zhang Xianlong, Wu Di, Wu Yongning, Li Guoliang
School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, China.
Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast, BT9 5DL, United Kingdom.
Biosens Bioelectron. 2021 Jan 15;172:112776. doi: 10.1016/j.bios.2020.112776. Epub 2020 Oct 28.
Inspired by the structure of the catalytically active center of natural laccase, a novel laccase mimics (named LM nanozymes) with a superior catalytic activity was successfully prepared by using glutathione (GSH) and copper (II) chloride as precursors via a facile hydrothermal method. The catalytically active center structure of LM nanozymes was revealed, which was constructed based on the numerous copper (Ⅰ) and copper (II) coordinating with thiol/amino group. The possible catalytic mechanism of LM nanozymes was also proposed. Similar to natural laccase, the prepared LM nanozymes can catalyze the oxidative coupling reaction between 2,4-dichlorophenol (2,4-DP) and 4-aminoantipyrine (4-AP) to produce an obvious red product. Compared with natural laccase, the LM nanozymes showed many outstanding advantages such as robust stability, lower cost, stronger catalytic activity and substrate affinity. Based on its excellent performances, LM nanozymes were employed as a powerful alternative to the natural enzyme in a traditional enzyme-linked immunosorbent assay (ELISA) to establish a nanozyme-based ELISA towards alpha-lactalbumin (allergenic protein). Impressively, a high-throughput and portable detection method was established by the integration of the nanozyme-based ELISA with a smartphone. The portable detection strategy achieved a limit of detection as low as 0.056 ng/mL with high specificity, and also showed excellent applicability in food sample analysis. This work not only enriches the diversities of nanozymes, but also broadens the promising applications of nanozymes in the biosensing area.
受天然漆酶催化活性中心结构的启发，以谷胱甘肽（GSH）和氯化铜（II）为前驱体，通过简便的水热法成功制备了一种具有优异催化活性的新型漆酶模拟物（命名为LM纳米酶）。揭示了LM纳米酶的催化活性中心结构，其基于大量与硫醇/氨基配位的铜（Ⅰ）和铜（II）构建而成。还提出了LM纳米酶可能的催化机制。与天然漆酶类似，所制备的LM纳米酶可催化2,4 - 二氯苯酚（2,4 - DP）和4 - 氨基安替比林（4 - AP）之间的氧化偶联反应，生成明显的红色产物。与天然漆酶相比，LM纳米酶具有许多突出优点，如稳定性强、成本低、催化活性和底物亲和力更强。基于其优异性能，LM纳米酶在传统酶联免疫吸附测定（ELISA）中作为天然酶的有力替代品，用于建立针对α - 乳白蛋白（过敏原蛋白）的基于纳米酶的ELISA。令人印象深刻的是，通过将基于纳米酶的ELISA与智能手机集成，建立了一种高通量便携式检测方法。该便携式检测策略实现了低至0.056 ng/mL的检测限，具有高特异性，并且在食品样品分析中也显示出优异的适用性。这项工作不仅丰富了纳米酶的多样性，还拓宽了纳米酶在生物传感领域的广阔应用前景。
