Abstract：
Quantitative microRNA (miRNA) detection is crucial for early breast cancer diagnosis and prognosis. However, quick and stable fluorescence sensing for miRNA identification is still challenging. This work developed a novel label-free detection method based on AuNPs etching for quantitatively detecting miRNA-155. A layer of AuNPs was grown on the surface of mesoporous silica nanoparticles (MSN) loaded with Rhodamine 6G (R6G) using seed-mediated growth, followed by probe attachment. In the presence of miRNA-155, the MSN@R6G@AuNP surface loses the protection of the attached probe, rendering AuNPs susceptible to etching by hydrochloric acid. This results in a significant fluorescent signal being released in the free space. The encapsulation with AuNPs effectively reduces signal leakage, while the rapid etching process shortens detection time. This strategy enables sensitive and fast detection with a detection range of 100 fM to 100 nM, a detection limit of 2.18 fM, and a detection time of 30 min. The recovery rate in normal human serum ranges from 99.02 % to 106.34 %. This work presents a simple biosensing strategy with significant potential for application in tumor diagnosis.
摘要：
定量检测微小RNA(miRNA)对早期乳腺癌的诊断和预后至关重要。然而,快速和稳定的荧光检测对miRNA的鉴定仍然具有挑战性。这项工作开发了一种基于AuNPs蚀刻的新型无标记检测方法，用于定量检测miRNA-155。使用种子介导的生长，在负载罗丹明6G（R6G）的介孔二氧化硅纳米颗粒（MSN）的表面上生长了一层AuNP，其次是探针附件。在miRNA-155的存在下，MSN@R6G@AuNP表面失去了连接探针的保护，使AuNP易受盐酸腐蚀。这导致在自由空间中释放显著的荧光信号。AuNP封装有效地减少了信号泄漏，而快速刻蚀工艺缩短了检测时间。该策略可实现灵敏和快速的检测，检测范围为100fM至100nM，检测限为2.18fM，和30分钟的检测时间。正常人血清的回收率为99.02％至106.34％。这项工作提出了一种简单的生物传感策略，具有在肿瘤诊断中应用的巨大潜力。
