In this work, we developed a simple and selective luminescence sensing system for detecting ascorbic acid (AA) based on NaGdF₄:Yb,Er@NaYF₄ upconversion nanoparticles (UCNPs) and oxidase-like CoOOH nanoflakes. When p-phenylenediamine (PPD) and oxidase-like CoOOH nanoflakes were added to the UCNPs solutions, PPD, as a typical substrate of oxidase, could be oxidized to PPDox. The luminescence intensity of UCNPs was quenched because PPDox could play a role as an energy acceptor. When AA was added to the above solution mixture, the CoOOH nanoflakes were destroyed, and then, the luminescence intensity was recovered. Under the best experimental conditions, the linear range for detection of AA was 0.8 to 280 μM, and the detection limit was 0.25 μM. Furthermore, the system could be applied to real sample analysis with satisfactory results.

中文翻译：

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基于NaGdF4：Yb，Er @ NaYF4纳米粒子和氧化酶样CoOOH纳米薄片的抗坏血酸的上转换发光检测

在这项工作中，我们基于NaGdF ₄：Yb，Er @ NaYF ₄上转换纳米粒子（UCNPs）和类似氧化酶的CoOOH纳米薄片，开发了一种简单而选择性的发光传感系统，用于检测抗坏血酸（AA）。当p将苯二胺（PPD）和类似氧化酶的CoOOH纳米片添加到UCNPs溶液中，PPD作为氧化酶的典型底物，可被氧化成PPDox。UCNPs的发光强度被猝灭了，因为PPDox可以充当能量受体。当将AA添加到上述溶液混合物中时，破坏了CoOOH纳米薄片，然后恢复了发光强度。在最佳实验条件下，AA的线性检测范围为0.8到280μM，检测极限为0.25μM。此外，该系统可用于实际样品分析，结果令人满意。