A new label-free fluorescent sensor for human immunodeficiency virus detection based on exonuclease III-assisted quadratic recycling amplification and DNA-scaffolded silver nanoclusters
A new label-free fluorescent sensor for human immunodeficiency virus detection based on exonuclease III-assisted quadratic recycling amplification and DNA-scaffolded silver nanoclusters
复制标题
基于核酸外切酶III辅助二次循环扩增和DNA支架银纳米簇的新型无标记荧光传感器用于人类免疫缺陷病毒检测
作者：
Yang Wen;Tian Jianniao;Wang Lijun;Fu Shui;Huang Hongyun;Zhao Yanchun;Zhao Shulin
基于荧光DNA支架银纳米团簇（DNA/AgNC）和自主核酸外切酶III（Exo III）辅助的循环信号放大技术，构建了一种用于检测人类免疫缺陷病毒基因（HIV-DNA）的无标记、高灵敏的荧光生物传感平台。一个长链DNA（X-DNA）分子可以与两个辅助DNA（F-DNA）分子和一个HIV-DNA分子杂交; Exo III使X-DNA断裂后释放出F-DNA和HIV-DNA。F-DNA与P-DNA（DNA/AgNCs的模板）结合，P-DNA被切割，体系的荧光被猝灭。该方法无需标记DNA链或构建复合物，一步完成，灵敏度高，检测限低至35 pM。同时，该方法即使对单个碱基错配也表现出良好的选择性。更重要的是，该方法能够监测真实的人类血清样本中的HIV-DNA;它在基因相关疾病的早期诊断中具有巨大的潜力。
A label-free and sensitive fluorescence biosensing platform for human immunodeficiency virus gene (HIV-DNA) detection has been fabricated based on luminescent DNA-scaffolded silver nanoclusters (DNA/AgNCs) and autonomous exonuclease III (Exo III)-assisted recycling signal amplification. One long-chain DNA (X-DNA) molecule can hybridize with two assistant DNA (F-DNA) molecules and one HIV-DNA molecule; after Exo III digests X-DNA to liberate F-DNA and HIV-DNA. F-DNA combines with P-DNA (template of DNA/AgNCs), accordingly, P-DNA is cut and the fluorescence of the system is quenched. This assay can finish in one-step without any labelling of the DNA chain or complex construction, and the strategy is sensitive with the detection limit as low as 35 pM. At the same time, the approach exhibits good selectivity even against a single base mismatch. What's more, the method is able to monitor HIV-DNA in real human serum samples; it holds great potential for early diagnosis in gene-related diseases.