Liu Shi Gang, Han Lei, Li Na, Xiao Na, Ju Yan Jun, Li Nian Bing, Luo Hong Qun
Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China.
J Mater Chem B. 2018 May 14;6(18):2843-2850. doi: 10.1039/c7tb03275g. Epub 2018 Apr 23.
Nanozymes are increasingly exploited as components in bioanalysis and diagnostics. Here, we report a fluorescence and colorimetric dual-mode assay for alkaline phosphatase (ALP) activity employing oxidase-like cobalt oxyhydroxide (CoOOH) nanoflakes. Colorless o-phenylenediamine (OPD), a substrate for oxidase, can be oxidized to a product (OxOPD) with yellow color and orange fluorescence in a CoOOH nanoflake solution. But, ascorbic acid (AA) is able to reduce CoOOH to cobalt ion (Co), which causes the decomposition and collapse of the CoOOH nanoflakes, and thereby the CoOOH nanoflakes are deprived of the oxidase-like property. Based on this principle, the fluorescence and colorimetric dual-mode detection of AA was achieved. Alkaline phosphatase (ALP) can make l-ascorbic acid-2-phosphate (AAP) hydrolyze to yield AA. As a result, with the help of AAP, the selective and sensitive dual-mode assay of ALP activity has been realized successfully by using fluorescence and UV-vis absorption spectroscopies. Quantitative analysis of ALP in human serum samples and an ALP inhibitor investigation were performed using this sensing system. Given the economical and sensitive properties, the proposed method based on CoOOH nanoflakes has great potential for not only probing ALP activity in biological systems but also screening potential ALP inhibitors. Meanwhile, in this study, a new insight has been provided into the application of CoOOH nanoflakes in the development of sensitive and convenient sensors.
纳米酶作为生物分析和诊断的组件正越来越多地得到应用。在此，我们报道了一种采用类氧化酶氢氧化氧钴（CoOOH）纳米片对碱性磷酸酶（ALP）活性进行荧光和比色双模式检测的方法。无色的邻苯二胺（OPD）作为氧化酶的底物，在CoOOH纳米片溶液中可被氧化为具有黄色和橙色荧光的产物（氧化型邻苯二胺，OxOPD）。但是，抗坏血酸（AA）能够将CoOOH还原为钴离子（Co），这会导致CoOOH纳米片分解和坍塌，从而使CoOOH纳米片失去类氧化酶特性。基于此原理，实现了对AA的荧光和比色双模式检测。碱性磷酸酶（ALP）可使l -抗坏血酸-2-磷酸酯（AAP）水解产生AA。因此，借助AAP，通过荧光光谱和紫外可见吸收光谱成功实现了对ALP活性的选择性和灵敏双模式检测。使用该传感系统对人血清样本中的ALP进行了定量分析并开展了ALP抑制剂研究。鉴于其经济且灵敏的特性，基于CoOOH纳米片的所提方法不仅在探测生物系统中的ALP活性方面，而且在筛选潜在的ALP抑制剂方面都具有巨大潜力。同时，在本研究中，为CoOOH纳米片在开发灵敏便捷传感器方面的应用提供了新的见解。
