核酸适配体功能化磁纳米颗粒富集-激光诱导荧光在线检测金黄色葡萄球菌

In this paper, we proposed a new assay for S.aureus detection through coupling nano-probe technology, aptamer recognition with laser-induced fluorescence detector. We used magnetic field and hydrodynamic drag force in capillary to separate and the laser-induced fluorescence detector to realize the on-line detection, via aptamer-conjugated magnetic nanoparticles for both recognition and preconcentration elements. The parameters were optimized: the concentration of magnetic nanoparticles, biotin-aptamer and FAM-aptamer was 1.0 mg/mL , 100 nmol/L and 120 nmol/L respectively and the flow velocity was 90 mm/min. Under optimal conditions, good linear responses were obtained between the fluorescence peak area and the concentration of S.aureus ranged from 6.7 CFU/mL to 6.7×104 CFU/mL (R2=0.987), with a limit of detection of 3 CFU/mL.The ability of the bioassay to detect S. aureus in real water samples was also tested.