Institute for Advanced Interdisciplinary Research, University of Jinan, Jinan 250022, PR China.
Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022, PR China.
Biosens Bioelectron. 2018 May 15;105:218-225. doi: 10.1016/j.bios.2018.01.025. Epub 2018 Jan 12.
In this work, an electrochemical biosensor based on Au nanorods (NRs) modified microfluidic paper-based analytical devices (μPADs) were constructed for sensitive detection of microRNA (miRNA) by using cerium dioxide - Au@glucose oxidase (CeO-Au@GOx) as an electrochemical probe for signal amplification. Au NRs were synthesized by in-situ growth method in μPADs surface to enhance the conductivity and modified hairpin probe through Au-S bonds. The construction of "the signal transducer layer" was carried out by GOx catalyzing glucose to produce HO, which was further electrocatalyzed by CeO. After the biosensor was constructed, an obvious electrochemical signal was observed from the reduction of HO. In order to make the detection more convincing, the visual detection was performed based on the oxidation of 3,3',5,5'-tetramethylbenzidine by HO with the help of Exonuclease I. The electrochemical biosensor provided a wide linear range of 1.0fM to 1000fM with a relatively low detection limit of 0.434fM by the electrochemical measurement. Linear range of 10fM to 1000fM with a relatively low detection limit of 7.382fM was obtained by visual detection. The results indicated the proposed platform has potential utility for detection of miRNA.
在这项工作中，构建了一种基于金纳米棒（AuNRs）修饰的微流控纸基分析器件（μPADs）的电化学生物传感器，通过使用二氧化铈-金@葡萄糖氧化酶（CeO-Au@GOx）作为电化学探针进行信号放大，实现对 microRNA（miRNA）的灵敏检测。AuNRs 通过原位生长法在 μPADs 表面合成，以增强导电性，并通过 Au-S 键修饰发夹探针。通过 GOx 催化葡萄糖产生 HO，进一步通过 CeO 电催化，构建“信号转换器层”。生物传感器构建后，可观察到 HO 还原产生的明显电化学信号。为了使检测更具说服力，在 Exonuclease I 的帮助下，基于 HO 对 3,3',5,5'-四甲基联苯胺的氧化进行了可视化检测。电化学测量得到的电化学生物传感器具有 1.0fM 至 1000fM 的宽线性范围和相对较低的检测限 0.434fM。通过可视化检测得到的线性范围为 10fM 至 1000fM，检测限为 7.382fM。结果表明，所提出的平台在 miRNA 的检测方面具有潜在的应用价值。
