Centre for Biomimetic Sensor Science, Nanyang Technological University, 637553 Singapore.
School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore.
ACS Appl Mater Interfaces. 2020 Jul 15;12(28):31270-31281. doi: 10.1021/acsami.0c09179. Epub 2020 Jul 1.
Over the past few decades, colorimetric assays have been developed for cost-effective and rapid on-site urinalysis. Most of these assays were employed for detection of biomarkers such as glucose, uric acid, ions, and albumin that are abundant in urine at micromolar to millimolar levels. In contrast, direct assaying of urinary biomarkers such as glycated proteins, low-molecular-weight reactive oxygen species, and nucleic acids that are present at significantly lower levels (nanomolar to picomolar) remain challenging due to the interferences from the urine sample matrix. State-of-the-art assays for detection of trace amounts of urinary biomarkers typically utilize time-consuming and equipment-dependent sample pretreatment or clean-up protocols prior to assaying, which limits their applicability for on-site analysis. Herein, we report a colorimetric assay for on-site detection of trace amount of generic biomarkers in urine without involving tedious sample pretreatment protocols. The detection strategy is based on monitoring the changes in optical properties of poly(3-(4-methyl-3'-thienyloxy)propyltriethylammonium bromide) upon interacting with an aptamer or a peptide nucleic acid in the presence and absence of target biomarkers of relevance for the diagnosis of metabolic complications and diabetes. As a proof of concept, this study demonstrates facile assaying of advanced glycation end products, 8-hydroxy-2'-deoxyguanosine and hepatitis B virus DNA in urine samples at clinically relevant concentrations, with limits of detection of ∼850 pM, ∼650 pM, and ∼ 1 nM, respectively. These analytes represent three distinct classes of biomarkers: (i) glycated proteins, (ii) low-molecular-weight reactive oxygen species, and (iii) nucleic acids. Hence, the proposed methodology is applicable for rapid detection of generic biomarkers in urine, without involving sophisticated equipment and skilled personnel, thereby enabling on-site urinalysis. At the end of the contribution, we discuss the opportunity to translate the homogeneous assay into a paper-based format.
在过去的几十年中，已经开发出了用于经济高效和快速现场尿液分析的比色测定法。这些测定法大多数用于检测生物标志物，例如葡萄糖、尿酸、离子和白蛋白，这些生物标志物在尿液中的浓度为微摩尔至毫摩尔级。相比之下，由于尿液样品基质的干扰，直接检测尿液中生物标志物（例如糖化蛋白、低分子量活性氧物质和核酸）仍然具有挑战性，这些生物标志物的浓度显著较低（纳摩尔至皮摩尔级）。用于检测痕量尿液生物标志物的最新技术测定法通常需要在测定之前使用耗时且依赖于设备的样品预处理或净化方案，这限制了它们在现场分析中的适用性。在这里，我们报告了一种无需繁琐的样品预处理方案即可现场检测尿液中痕量通用生物标志物的比色测定法。该检测策略基于在存在和不存在与代谢并发症和糖尿病诊断相关的靶生物标志物的情况下，监测聚（3-（4-甲基-3'-噻吩氧基）丙基三乙基溴化铵）与适体或肽核酸相互作用时光学性质的变化。作为概念验证，本研究在临床相关浓度下，在尿液样品中简便地测定了晚期糖基化终产物、8-羟基-2'-脱氧鸟苷和乙型肝炎病毒 DNA，检测限分别约为 850 pM、650 pM 和 1 nM。这些分析物代表了三种不同类别的生物标志物：（i）糖化蛋白，（ii）低分子量活性氧物质和（iii）核酸。因此，所提出的方法适用于快速检测尿液中的通用生物标志物，无需使用复杂的设备和熟练的人员，从而实现了现场尿液分析。在本文的结尾，我们讨论了将均相测定法转化为基于纸张的格式的机会。
