Cancer detection is still a major challenge in public health. Identification of oncogene is the first step toward solving this problem. Studies have revealed that various cancers are associated with miRNA expression. Therefore, the sensitive detection of miRNA is substantially important to solve the cancer problem. In this study, let-7a, a representative substance of miRNA, was selected as the detection target. With the assistance of magnetic beads commonly used in biosensors and self-synthesized graphene oxide materials, specificity and sensitivity detection of the target gene let-7a were achieved via protease-free signal amplification. The limit of detection (LOD) was as low as 15.015pM. The fluorescence signal intensity showed a good linear relationship with the logarithm of let-7a concentration. The biosensor could also detect let-7a in complex human serum samples. Overall, this fluorescent biosensor is not only simple to operate, but also strongly specificity to detect let-7a. Therefore, it has substantial potential for application in the early diagnosis of clinical medicine and biological research.

中文翻译：

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用于疾病诊断的磁珠和GO辅助无酶信号放大荧光生物传感器

癌症检测仍然是公共卫生领域的一项重大挑战。癌基因的鉴定是解决这一问题的第一步。研究表明，多种癌症与 miRNA 表达有关。因此，miRNA的灵敏检测对于解决癌症问题具有重要意义。本研究选择miRNA的代表物质let-7a作为检测靶标。借助生物传感器常用的磁珠和自行合成的氧化石墨烯材料，通过无蛋白酶信号放大实现了对目标基因let-7a的特异性和灵敏度检测。检测限 (LOD) 低至 15.015pM。荧光信号强度与let-7a浓度的对数呈良好的线性关系。该生物传感器还可以检测复杂的人血清样本中的let-7a。总体而言，该荧光生物传感器不仅操作简单，而且对let-7a的检测具有很强的特异性。因此，它在临床医学的早期诊断和生物学研究中具有巨大的应用潜力。