Studies have shown that microRNAs affect the development of tumors. In many cases, they can be applied as biomarkers for the diagnosis of cancer; therefore, simple and sensitive analytical methods for detection of miRNAs are necessary. In this study, miR-141, which is used to diagnose several types of cancer, was detected in water and serum samples using a biosensor designed based on streptavidin-coated magnetic beads (SMBs), complementary sequences of miR-141 and PicoGreen as the fluorescent dye. The method is relatively fast and simple. Briefly, in the presence of miR-141, the complementary sequence forms a DNA:RNA double–strand on the surface of SMBs with intercalated PicoGreen. Upon attachment of the PicoGreen, the fluorescence intensity increased significantly (1000-fold). In the absence of a target, only single-stranded DNA (complementary strand of miR-141) existed on the surface of the SMBs. The fluorescence of the PicoGreen was low. The results revealed that the detection limits of the biosensor for miR-141 were 70 and 113.8 nmol L⁻¹ in deionized water and serum samples, respectively.

研究表明，microRNA会影响肿瘤的发展。在许多情况下，它们可以用作诊断癌症的生物标志物。因此，需要一种简单而灵敏的分析方法来检测miRNA。在这项研究中，使用基于链霉亲和素包被的磁珠（SMBs），miR-141和PicoGreen互补序列设计的生物传感器，在水和血清样品中检测到了用于诊断几种癌症的miR-141。荧光染料。该方法相对快速且简单。简而言之，在存在miR-141的情况下，互补序列在插入了PicoGreen的SMB表面上形成DNA：RNA双链。附着PicoGreen后，荧光强度显着增加（1000倍）。在没有目标的情况下，SMB的表面仅存在单链DNA（miR-141的互补链）。PicoGreen的荧光很低。结果表明，miR-141生物传感器的检出限分别为70和113.8 nmol L去离子水和血清样品中分别为^-1。