检出限
化学
杂交探针
细菌
DNA
16S核糖体RNA
电极
电化学气体传感器
生物物理学
纳米技术
电化学
色谱法
生物化学
材料科学
生物
基因
遗传学
物理化学
作者
Jialin Zhang,Hongli Yang,Wenjing Liu,He‐Rui Wen,Fengjiao He
标识
DOI:10.1016/j.aca.2021.339266
摘要
Diseases caused by bacteria pose great challenges to human health. The key to reduce disease transmission and mortality is to develop accurate and rapid methods for the detection and identification of bacteria. Herein, a rapid bacteria 16S rDNA electrochemical sensor based on target-triggered hairpin self-assembly and tripedal DNA walker (TD walker) amplification strategy was constructed. Specific variable region of 16S rDNA fragment of bacteria was used as biomarker. The target-triggered hairpin self-assembly strategy was used to prepare a TD walker. The hairpin DNA probes labeled with ferrocene (Fc) were designed and modified on surface of electrode. The "legs" of TD walker hybridized with three hairpin probes and opened their hairpin structures. Exo III enzyme recognised hybrid duplexes and selectively digest hairpin probes. The "legs" of TD walker was released and hybridized with the other three hairpin probes. In this way, the enzyme drived the walkers to walk along electrode interface, until hairpin DNA probes were all removed from the electrode, the Fc was far away from electrode interface. A significantly current reduction signal was obtained and bacteria were detected by recording this response. This strategy was low-cost and scalable, it could continuously recycle low-concentration targets, thus enhanced the detection sensitivity. As the proof-of-concept work, the electrochemical sensor was utilized as detector. The limit of detection (LOD) of detecting Staphylococcus aureus (S. aureus) was 20 CFU mL-1 and detection time was less than 3 h. It was expected to be widely used in clinical early diagnosis.
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