A rapid and visual aptasensor for Lipopolysaccharides detection based on the bulb-like triplex turn-on switch coupled with HCR-HRP nanostructures.
A rapid and visual aptasensor for Lipopolysaccharides detection based on the bulb-like triplex turn-on switch coupled with HCR-HRP nanostructures.
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DOI：
10.1016/j.bios.2016.10.012
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发表时间：
2017-03
影响因子：
12.6
通讯作者：
Wentao Xu;Jingjing Tian;Xiangli Shao;Longjiao Zhu;Kunlun Huang;Yunbo Luo
中科院分区：
文献类型：
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作者：
Wentao Xu;Jingjing Tian;Xiangli Shao;Longjiao Zhu;Kunlun Huang;Yunbo Luo
对于已报道的适配子传感器，由于单链分子信标的报告标记或双链DNA链置换的阻碍，适配子对靶标的敏感性和选择性往往受到抑制。为了解决传统方法中核酸适体亲和力下降的问题，实现内毒素的现场快速检测，我们研制了一种新颖的结构转换适体传感器，该传感器以灯泡状三链开启开关(BTTS)为有效的分子识别和信号转导元件，以链霉亲和素-辣根过氧化物酶修饰杂交链式反应(HCR-HRP)纳米复合材料为信号放大和信号报告元件。在有内毒素存在的情况下，球状的内毒素-适配子(BLA)与内毒素形成内毒素/适配子复合体，而BTTS则分解并释放游离的桥式探针(BP)，实现分子识别和信号转导。用固定化捕获探针(CP)捕获固定化BP，触发杂交链式反应(HCR)放大开关信号，然后用链霉亲和素-辣根过氧化物酶(SA-HRP)修饰HCR-HRP纳米结构以输出比色信号。在不到4小时的时间里，所提出的生物传感器用便携式分光光度计定量检测内毒素的下限为50微克/毫升，用肉眼半定量检测内毒素的下限为20微克/毫升，为未来临床诊断、食品安全和环境监测中的内毒素检测开辟了新的机遇。
For previously reported aptasensor, the sensitivity and selectivity of aptamers to targets were often suppressed due to the reporter label of single-stranded molecular beacon or hindrance of the duplex DNA strand displacement. To solve the affinity declining of aptamers showed in traditional way and realize on-site rapid detection of Lipopolysaccharides (LPS), we developed an ingenious structure-switching aptasensor based on the bulb-like triplex turn-on switch (BTTS) as the effective molecular recognition and signal transduction element and streptavidin-horseradish peroxidase modified hybridization chain reaction (HCR-HRP) nanocomposites as the signal amplifier and signal report element. In the presence of LPS, the bulb-like LPS-aptamer (BLA) and LPS formed the LPS/aptamer complex, while the BTTS disassembled and liberated the dissociative bridge probes (BP) to achieve molecular recognition and signal transduction. Immobilized BP, captured by immobilized capture probes (CP), triggered hybridization chain reactions (HCR) to amplify the switching signal, and the HCR products were then modified with streptavidin-horseradish peroxidase (SA-HRP) to form HCR-HRP nanostructures to output colorimetric signals. In less than four hours, the proposed biosensor showed a detection limit of 50 pg/mL of LPS quantitatively with the portable spectrophotometer and the observation limit of 20 ng/mL semi-quantitatively with the naked eye, opening up new opportunities for LPS detection in future clinical diagnosis, food security and environment monitoring.