Colorimetric determination of cysteine based on Au@Pt nanoparticles as oxidase mimetics with enhanced selectivity
Colorimetric determination of cysteine based on Au@Pt nanoparticles as oxidase mimetics with enhanced selectivity
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DOI：
10.1007/s00604-021-05091-7
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发表时间：
2022-01-01
影响因子：
5.7
通讯作者：
Huan, Yanfu
中科院分区：
文献类型：
--
作者：
Chi, Hui;Cui, Xiaoqian;Huan, Yanfu
基于海胆状Au@Pt纳米粒子（Au@Pt NPs），建立了一种无H2 O2比色法，用于半胱氨酸（Cys）的灵敏和选择性测定。我们验证了Au@Pt纳米颗粒的内在氧化酶样活性。它们可作为人工模拟氧化酶，在溶解氧的辅助下催化3，3 '，5，5'-四甲基联苯胺（TMB）的氧化，避免了比色法测定半胱氨酸时使用H2 O2。此外，从其他两个biothiol类似物，同型半胱氨酸和谷胱甘肽的半胱氨酸的歧视，可以很容易地实现通过一个简单的老化过程。向该比色系统中加入HNO 3，通过将ox-TMB（TMB的氧化形式）氧化成联苯醌（DPQ）来终止反应，从而在450 nm处产生DPQ的特征吸收峰。通过记录450 nm处的吸光度，可以消除当650 nm（ox-TMB的特征吸收峰）用作吸收波长时来自聚集的Au@Pt NP（670 nm处的吸收峰）的干扰。我们研究了这种无H2 O2比色协议，并获得了高灵敏度，检测限为1.5 nM和相对较高的选择性。进一步探索了真实的样品的分析性能。该Au@Pt NP无H2 O2比色方案对于不同场景下实际样品中Cys的灵敏和选择性测定具有重要意义。
A H2O2-free colorimetric protocol based on urchin-like Au@Pt nanoparticles (Au@Pt NPs) has been developed for the sensitive and selective determination of cysteine (Cys). We verified the intrinsic oxidase-like activity of the Au@Pt NPs. They can act as artificial mimic oxidases to catalyse the oxidization of 3,3 ',5,5 '-tetramethylbenzidine (TMB) with the assistance of dissolved oxygen, avoiding the use of H2O2 in the colorimetric determination of Cys. In addition, the discrimination of Cys from the other two biothiol analogues, homocysteine and glutathione, can be easily realized through a simple ageing process. HNO3 is added to this colorimetric system to terminate the reaction by oxidizing ox-TMB (oxidized form of TMB) to diphenoquinone (DPQ), thus generating a characteristic absorption peak of DPQ at 450 nm. By recording the absorbance at 450 nm, interference from the aggregated Au@Pt NPs (absorption peak at 670 nm) when 650 nm (the characteristic absorption peak of ox-TMB) is used as the absorption wavelength can be eliminated. We investigated this H2O2-free colorimetric protocol and obtained high sensitivity, with a detection limit of 1.5 nM and relatively high selectivity. The analytical performance for real samples was further explored. The Au@Pt NP-based H2O2-free colorimetric protocol is of great significance for the sensitive and selective determination of Cys in practical samples in different scenarios.