In clinical diagnosis, monitoring of uric acid (UA) is generally realized by combining uricase with natural peroxidase. The use of bio-enzymes, however, shadows some highlights of these methods due to their vulnerable activities against environments. Herein, we report a novel biosensor for the natural enzyme-free colorimetric detection of UA by using CoP nanosheet arrays grown on Ni foam (NF) as a monolithic peroxidase mimic. The integrated nanozyme can be put into and taken out from reaction systems conveniently with only tweezers, making it possible for on-demand analysis. As demonstrated, the obtained CoP/NF exhibits outstanding peroxidase-like activity to trigger the oxidation reaction of colorless 3,3'5,5'-tetramethylbenzidine (TMB) to a blue product (TMBox) mediated by H2O2. It is found that the blue TMBox can be reduced to colorless TMB again by UA selectively, thus the presence of UA in solutions will suppress the color reaction of TMB. Based on this principle, an uricase-free biosensor is developed for the photometric determination of UA, providing a wide detection range of 1-200 μM and a limit of detection down to 1.0 μM. In addition, the fabricated biosensor can be applied for measuring UA in clinical samples with merits of simple operation and good reliability, exhibiting its great promise in clinical diagnosis.

中文翻译：

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通过集成的 CoP 纳米片阵列作为整体过氧化物酶模拟物实现的无尿酸酶按需比色生物传感

在临床诊断中，一般通过尿酸酶与天然过氧化物酶的结合来实现尿酸（UA）的监测。然而，由于它们对环境的脆弱活动，生物酶的使用掩盖了这些方法的一些亮点。在此，我们报告了一种新型生物传感器，通过使用在泡沫镍 (NF) 上生长的 CoP 纳米片阵列作为整体过氧化物酶模拟物，用于 UA 的天然无酶比色检测。集成的纳米酶只需镊子就可以方便地放入和取出反应系统，使得按需分析成为可能。正如所证明的，获得的 CoP/NF 表现出出色的过氧化物酶样活性，以触发无色 3,3'5,5'-四甲基联苯胺 (TMB) 氧化反应为由 H2O2 介导的蓝色产物 (TMBox)。发现蓝色的TMBox可以被UA选择性地再次还原为无色的TMB，因此溶液中UA的存在会抑制TMB的显色反应。基于此原理，开发了一种无尿酸酶生物传感器用于 UA 的光度测定，提供 1-200 μM 的宽检测范围和低至 1.0 μM 的检测限。此外，所制备的生物传感器可用于测量临床样品中的UA，具有操作简单、可靠性好等优点，在临床诊断中具有广阔的应用前景。