适体
费斯特共振能量转移
荧光
材料科学
光子上转换
化学
猝灭(荧光)
二硫化钨
纳米颗粒
检出限
纳米技术
生物传感器
光化学
大肠杆菌
离子
色谱法
生物化学
生物
基因
物理
量子力学
有机化学
冶金
遗传学
作者
Pingyue Wang,Ancheng Wang,Mehedi Hassan,Qin Ouyang,Huanhuan Li,Quansheng Chen
标识
DOI:10.1016/j.snb.2020.128434
摘要
In this study, we have design a new biosensor for E. coli, based on the fluorescence resonance energy transfer (FRET) between aptamer modified upconversion nanoparticles (UCNPs) as donors and layered tungsten disulfide (WS2) nanosheets as the effective acceptor. The aptamer modified-UCNPs can be fetched nearest to the WS2 surface, because of the potent van der Waals force between the nucleobases of aptamer and the basal plane of WS2. The spectral overlap between UCNPs fluorescence emission and WS2 absorption permits the occurrence of FRET, resulted in quenching of upconversion fluorescence. In the presence of E. coli, the specific aptamer preferentially bind to E. coli, causing changes in the conformation of aptamer, a phenomenon directs the dissociation of mixing probe away from the surface of WS2 nanosheets and therefore parts of the quenched fluorescence of UCNPs was retrieved. The fluorescence intensity increased with the raised concentration of E. coli. The aptasensor exhibited limitary over the concentration range 85 to 85 × 107 cfumL−1 for E. coli and the detection limit (LOD) was 17 cfumL−1. In addition, the proposed biosensing method comprehended huge advantages including the facile operation procedure, high sensitivity and selectivity, which confer a great potential for the quantification of E. coli in medical diagnostics, food and environmental analysis.
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