Shen Fumiao, Cheng Yuliang, Xie Yunfei, Yu Hang, Yao Weirong, Li Hung-Wing, Guo Yahui, Qian He
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.
Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
Anal Biochem. 2019 Oct 15;583:113365. doi: 10.1016/j.ab.2019.113365. Epub 2019 Jul 17.
DNA-templated silver nanoclusters (DNA-AgNCs) is a kind of fluorescent nanoclusters in-situ synthesized on DNA, thereby giving the DNA probe an inherent function of label-free signal output. Herein, the DNA-AgNCs with a GCC-loop-structure which has a quantum field of 51.6% was firstly proposed. It was proved that the addition of the double-stranded structure on the GCC-loop drastically enhanced the fluorescence intensity of the AgNCs. Through the further studies of the relationship between DNA secondary structure and AgNCs, a kind of DNA-AgNCs-probe was designed based on the change of the secondary structure which was induced by the target strand. By this, the fluorescence signal of probe was in "turn on" mode. The probe system could be directly used for the detection of Norovirus RNA, which had a linearity of 20 nM to 1.8 μM with a detection limit of 18 nM. Moreover, this detection platform was also selective to differentiate mismatched RNA. It was expected to be a universal method for different RNA detection by changing the recognition sequence of the probe.
DNA模板化银纳米簇（DNA-AgNCs）是一种在DNA上原位合成的荧光纳米簇，从而赋予DNA探针无标记信号输出的固有功能。在此，首次提出了具有GCC环结构且量子产率为51.6%的DNA-AgNCs。结果表明，在GCC环上添加双链结构可显著增强AgNCs的荧光强度。通过进一步研究DNA二级结构与AgNCs之间的关系，基于靶链诱导的二级结构变化设计了一种DNA-AgNCs探针。据此，探针的荧光信号呈“开启”模式。该探针系统可直接用于诺如病毒RNA的检测，线性范围为20 nM至1.8 μM，检测限为18 nM。此外，该检测平台对区分错配RNA也具有选择性。通过改变探针的识别序列，有望成为一种用于不同RNA检测的通用方法。
