Label-Free Analysis of H5N1 Virus Based on Three-Segment Branched DNA-Templated Fluorescent Silver Nanoclusters
Ying Zhang, Fei Mu, Yefan Duan, Qi Li, Yating Pan, Hongfang Du, Panpan He, Xizhong Shen, Zhimin Luo, Changfeng Zhu, Lianhui Wang
Abstract
Since H5N1 virus is a highly infectious pathogen that causes outbreaks of avian influenza, developing a sensitive and rapid diagnostic platform to sense it becomes significant. Here, a novel label-free fluorescence sensing platform based on DNA-templated silver nanoclusters (DNA-Ag NCs) is developed to detect the H5N1 gene sequence representing H5N1 virus. The three-segment-branched DNA structure with closed cytosine-rich loop is designed as an effective template to produce fluorescent Ag NCs, which is different with the previous design of cytosine-rich loop formed by hairpin-like single-stranded DNA or double-stranded DNA. The proposed fluorescence detection approach gives a wide linear range (500 pM-2 μM) and a low detection limit (500 pM) to sense H5N1 gene sequence. Furthermore, selective analysis of target DNA shows that our constructed analytical strategy has a high selectivity to H5N1 gene sequence. It is regarded as a promising method for highly sensitive and selective sensing of H5N1 virus.