MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
Department of Thoracic Surgery, Sun Yat-Sen University Cancer Center, Guangzhou 510060, China; Guangdong Esophageal Cancer Institute, Guangzhou 510060, China; State Key Laboratory of Oncology in South China, Guangzhou 510060, China; Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, China.
Biosens Bioelectron. 2017 Jan 15;87:931-940. doi: 10.1016/j.bios.2016.09.043. Epub 2016 Sep 12.
MicroRNAs (miRNAs) have been proved to be potential biomarkers in early cancer diagnosis. It is of great significance for rapid and sensitive detection of miRNAs, particularly with point-of-care (POC) diagnosis. Herein, it is the first time to construct quantum dots (QDs)-labeled strip biosensor based on target-recycled nonenzymatic amplification strategy for miRNA detection. In the system, QDs were served as bright, photostable signal labels, which endow this biosensor with good detection efficiency. Moreover, a target-recycled amplification strategy relies on sequence-specific hairpins strand displacement process without the assistance of enzymes, was introduced to further improve the sensitivity. Meanwhile eliminating the requirement of environment-susceptible enzyme protein makes it easy to preserve and enhances the stability and reproducibility of this sensor. Benefiting from these outstanding characteristics, this platform exhibited a good detection sensitivity range from 2fmol to 200fmol with a limit of 200amol, using only 20μL of sample within 80min. The assay was also 10-fold more sensitive than that with a conventional colloidal gold-based test strip for miRNA detection. Additionally, the analysis of miRNA in various tumor cell extracts was in accordance with the performance of quantitative realtime polymerase chain reaction (qRT-PCR). Clinical tumor samples were also tested, and 16 of 20 samples gave out positive signals, which demonstrated the practical application capacity of the biosensor. Therefore, the proposed biosensor holds great promise for potential POC applications and early cancer diagnosis.
微小 RNA（miRNAs）已被证明是癌症早期诊断的潜在生物标志物。因此，快速、灵敏地检测 miRNA 具有重要意义，尤其是在即时检测（POC）诊断中。在此，首次构建了基于靶标循环非酶扩增策略的量子点（QDs）标记条带生物传感器用于 miRNA 检测。在该系统中，QDs 用作明亮、光稳定的信号标记，使该生物传感器具有良好的检测效率。此外，引入了一种依赖于序列特异性发夹链置换过程的靶标循环扩增策略，无需酶的辅助，进一步提高了灵敏度。同时消除了对环境敏感的酶蛋白的要求，使传感器易于保存，并提高了其稳定性和重现性。得益于这些优异的特性，该平台在 80min 内仅使用 20μL 样本，检测范围从 2fmol 到 200fmol，检测限为 200amol。与传统的基于胶体金的 miRNA 检测测试条相比，该检测方法的灵敏度提高了 10 倍。此外，对各种肿瘤细胞提取物中的 miRNA 进行分析的结果与定量实时聚合酶链反应（qRT-PCR）的性能一致。对临床肿瘤样本也进行了检测，20 个样本中有 16 个给出了阳性信号，证明了该生物传感器的实际应用能力。因此，该生物传感器在即时检测和癌症早期诊断方面具有广阔的应用前景。
