The detection of biomarkers is crucial for assessing disease status and progression. Uric acid (UA), a common biomarker in body fluids, plays an important role in the diagnosis and monitoring of conditions such as hyperuricemia, chronic kidney disease, and cardiovascular disease. However, the low concentration of UA in non-invasive body fluids, combined with numerous interfering substances, makes its detection challenging. Therefore, there is a pressing need to develop advanced sensor platforms that exhibit both high sensitivity and excellent specificity for accurate monitoring of UA levels in various body fluids. In this study, an electrochemical sensing system is developed by integrating a cascade interference-removal zone and a target-response zone on a wooden channel membrane (CM) for the pretreatment-free detection of UA in body fluids. In this design, cysteine-doped ZIF-67(Co) nanocrystals, a mimic with multi-enzyme activity, are modified in the interference-removal zone. The target-response zone on the other side of the CM is contacted with a solution containing Fe³⁺ and [Fe(CN)₆^]3– ions. Using saliva as a proof-of-concept, the interference species, including ascorbic acid (AA), dopamine (DA), and glutathione (GSH), are oxidized and removed when passing through the interference-removal zone, while UA reaches the target-response zone and triggers the growth of Prussian blue (PB) on site. Utilizing the peroxidase-like activity of PB, UA concentration is directly determined based on changes in transmembrane ion currents. The resulting sensing system exhibits higher sensitivity than commercial UA meters and demonstrates straightforward, continuous, and non-invasive monitoring of UA in saliva after consuming purine-rich foods. The technology provides a simple, reliable and low-cost device for sensing UA in complex biological matrices. Moreover, the CM based sensing device also provides the benefit of being incineratable and biodegradable, reducing medical and electronic waste, making it eco-friendly for daily diagnostics.

中文翻译：

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在 Wood 通道上设计干扰去除和目标响应级联区，用于直接检测唾液中的尿酸


生物标志物的检测对于评估疾病状态和进展至关重要。尿酸 （UA） 是体液中的常见生物标志物，在诊断和监测高尿酸血症、慢性肾病和心血管疾病等疾病中起着重要作用。然而，非侵入性体液中 UA 的低浓度，再加上许多干扰物质，使其检测具有挑战性。因此，迫切需要开发具有高灵敏度和出色特异性的先进传感器平台，以准确监测各种体液中的 UA 水平。本研究通过在木通道膜 （CM） 上集成级联干扰去除区和目标响应区，开发了一种电化学传感系统，用于体液中 UA 的免预处理检测。在该设计中，半胱氨酸掺杂的 ZIF-67（Co） 纳米晶体（一种具有多酶活性的模拟物）在干扰去除区被修饰。CM 另一侧的目标响应区与含有 Fe³⁺ 和 [Fe（CN）₆^]3– 离子的溶液接触。使用唾液作为概念验证，包括抗坏血酸 （AA）、多巴胺 （DA） 和谷胱甘肽 （GSH） 在内的干扰物质在通过干扰去除区时被氧化和去除，而 UA 到达目标响应区并触发普鲁士蓝 （PB） 的生长现场。利用 PB 的过氧化物酶样活性，根据跨膜离子电流的变化直接测定 UA 浓度。由此产生的传感系统表现出比商用 UA 仪表更高的灵敏度，并展示了在食用富含嘌呤的食物后对唾液中的 UA 进行直接、连续和无创的监测。 该技术为在复杂生物基质中传感 UA 提供了一种简单、可靠且低成本的设备。此外，基于 CM 的传感设备还具有可焚烧和可生物降解的优势，减少了医疗和电子废物，使其对日常诊断非常环保。