Sensitive Detection of BRCA1 Gene Based on Target Proximity Induced Quenching of the Fluorescence of Copper Nanoclusters

The mutations of breast cancer susceptibility gene 1 (BRCA1) play an important role in inherited breast cancers. Thus, the sensitive assay of the BRCA1 gene is extremely important for disease diagnosis and human health. Herein, a fast, sensitive and selective assay technique has been constructed based on fluorescent copper nanoclusters (CuNCs). The CuNCs were successfully formed with poly(AT-TA) double stranded DNA (dsDNA) as template. In the absence of the target, a strong red emission was observed under 365 nm ultraviolet (UV) lamp and a big fluorescence response was obtained. However, in the presence of BRCA1 gene, there was only weak red emission and a low response signal was produced because of the target-proximity induced quenching of the fluorescence of CuNCs. The linear range for the BRCA1 gene assay was 2-600 nM, and the limit of detection was 2 nM. The assay technique showed good selectivity, good stability and satisfactory recoveries for the detection of BRCA1 gene in diluted serum samples. Moreover, by integrating a UV lamp and a smartphone, the fluorescence sensor would be transferred to a microfluidic chip, providing a prospective application in point-of-care for monitoring breast cancer risk.

乳腺癌易感基因1（breast cancer susceptibility gene 1，BRCA1）的突变在遗传性乳腺癌中发挥着关键作用。因此，BRCA1基因的灵敏检测方法对于疾病诊断与人类健康至关重要。本研究构建了一种基于荧光铜纳米团簇（fluorescent copper nanoclusters，CuNCs）的快速、灵敏且选择性优异的检测技术。该荧光铜纳米团簇以聚(AT-TA)双链脱氧核糖核酸（double stranded DNA，dsDNA）为模板成功合成。在无靶标存在的情况下，于365 nm紫外（ultraviolet，UV）灯下可观察到强烈的红色荧光发射，并获得较强的荧光响应信号。然而，当体系中存在BRCA1基因时，因靶标邻近诱导引发荧光铜纳米团簇的荧光猝灭，仅能观察到微弱的红色荧光，且响应信号较低。该检测方法对BRCA1基因的线性检测范围为2~600 nM，检出限为2 nM。该检测技术展现出良好的选择性与稳定性，且在稀释血清样本的BRCA1基因检测中获得了令人满意的回收率。此外，通过集成紫外灯与智能手机，该荧光传感器可被集成至微流控芯片中，为乳腺癌风险监测的即时检测（point-of-care）提供了极具潜力的应用前景。