Successful construction of a detection method for () based on the synergy of hybridization chain reaction (HCR) and fluorescence was realized in this paper. First, the aptamer modified with the quenching group Black Hole Quencher-1 acid (BHQ1) was immobilized on the magnetic beads in combination with the complementary chain of the aptamer modified with 6-carboxyfluorescein (6-FAM). Second, and cDNA-6-FAM immobilized on magnetic beads competitively bound to the aptamer. Finally, the cDNA-6-FAM was released after magnetic separation acted as a promoter to trigger HCR amplification when the target presented. The fluorescence signal could be significantly improved by the combination of green SYBR Green I (SGI) and HCR long double-stranded DNA and the fluorescent synergy of 6-FAM and SGI. Because of the separation of target and its aptamer, the trigger strand was abstracted by magnetic separation. There was no HCR to generate long double-stranded DNA, and the fluorescence of excess hairpin/SGI could be adsorbed through UIO66 so that only a very low background signal was detected. This fluorescent sensor was capable of monitoring in the range of 10–3.2 × 10 CFU mL with a limit of detection as low as 1.5 CFU mL. Because of the excellent properties of the aptasensor and the validity of SGI fluorescence synergy, this HCR enzyme-free amplification strategy could be generalized to other areas.

中文翻译：

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UIO66低背景信号和荧光协同策略用于高灵敏检测鼠伤寒沙门氏菌

本文成功构建了基于杂交链式反应(HCR)和荧光协同作用的()检测方法。首先，将猝灭基团Black Hole Quencher-1 Acid (BHQ1)修饰的适体与6-羧基荧光素(6-FAM)修饰的适体的互补链结合固定在磁珠上。其次，固定在磁珠上的cDNA-6-FAM与适体竞争性结合。最后，磁分离后释放出cDNA-6-FAM，作为​​启动子，在靶标出现时触发HCR扩增。绿色SYBR Green I (SGI)和HCR长双链DNA的组合以及6-FAM和SGI的荧光协同作用可以显着改善荧光信号。由于靶标与其适体分离，通过磁力分离提取触发链。没有HCR产生长双链DNA，多余的发夹/SGI的荧光可以通过UIO66吸附，因此仅检测到非常低的背景信号。该荧光传感器能够监测 10–3.2 × 10 CFU mL 的范围，检测限低至 1.5 CFU mL。由于适配体传感器的优异性能和SGI荧光协同作用的有效性，这种HCR无酶扩增策略可以推广到其他领域。