Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China.
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China.
Talanta. 2019 May 15;197:599-604. doi: 10.1016/j.talanta.2019.01.087. Epub 2019 Jan 25.
The accurate quantification of hydrogen peroxide (HO) and glucose is essential significance in clinical diagnosis. Herein a selective and sensitive ratiometric fluorescent nanosensor was developed for the determination of HO and glucose by integrating peroxidase-like catalytic and fluorescent bifunctional properties of glutathione protected gold nanoclusters (GSH-AuNCs). The GSH-AuNCs exhibit inherent peroxidase-like activity and accelerate the decomposition of HO into hydroxyl radicals. The produced hydroxyl radicals oxidize terephthalic acid (TA), a typical non-fluorescent substrate of peroxidase, to a highly fluorescent product hydroxyterephthalate (TAOH). Upon excitation with single-wavelength at 315 nm, dual-emission fluorescence peaks were recorded at 430 and 600 nm simultaneously. The fluorescence signal of TAOH at 430 nm continuously increased with increasing the concentration of HO while the fluorescence signal of GSH-AuNCs at 600 nm remained unchangeable. Based upon on these facts, a ratiometric fluorescent nanosensor was fabricated for HO assay with TAOH as response unit and GSH-AuNCs as reference, respectively. By converting glucose into HO with catalytic oxidation of glucose oxidase (GOx), this nanosensor was further exploited for glucose assay. Under the optimum conditions, the detection limits of 10 nmol/L HO and 20 nmol/L glucose were acquired. The relative standard deviations were less than 5% for both HO and glucose (5.0 μmol/L solution, n = 11). The practicability of the nanosensor was verified by the determination of glucose in human serum samples. This nanosensor can be easily expanded as a general platform for the detection of other substances involving HO produced or consumed.
过氧化氢（HO）和葡萄糖的精确定量在临床诊断中具有重要意义。本文通过整合谷胱甘肽保护的金纳米簇（GSH-AuNCs）的过氧化物酶样催化和荧光双功能特性，开发了一种用于测定 HO 和葡萄糖的选择性和灵敏的比率荧光纳米传感器。GSH-AuNCs 具有内在的过氧化物酶样活性，并加速 HO 分解为羟基自由基。产生的羟基自由基将邻苯二甲酸（TA），一种典型的过氧化物酶非荧光底物，氧化为高荧光产物羟邻苯二甲酸（TAOH）。在 315nm 单波长激发下，同时记录到 430nm 和 600nm 的双发射荧光峰。随着 HO 浓度的增加，TAOH 在 430nm 的荧光信号不断增加，而 GSH-AuNCs 在 600nm 的荧光信号保持不变。基于这些事实，以 TAOH 作为响应单元，GSH-AuNCs 作为参考，构建了用于 HO 测定的比率荧光纳米传感器。通过葡萄糖氧化酶（GOx）的催化氧化将葡萄糖转化为 HO，该纳米传感器进一步用于葡萄糖测定。在最佳条件下，HO 的检测限为 10nmol/L，葡萄糖的检测限为 20nmol/L。HO 和葡萄糖的相对标准偏差均小于 5%（5.0μmol/L 溶液，n=11）。通过测定人血清样品中的葡萄糖验证了纳米传感器的实用性。该纳米传感器可轻松扩展为用于检测涉及 HO 产生或消耗的其他物质的通用平台。
