基于纳米金标记的金黄色葡萄球菌可视化检测方法研究

目的 以纳米金为载体, 对金黄色葡萄球菌进行可视化检测。方法 将与金黄色葡萄球菌目标序列互补的DNA 1和DNA 2连接到纳米金上, 当体系中出现金黄色葡萄球菌目标序列时, 两条短链DNA就会与目标序列杂交, 使纳米金之间的距离拉近, 从而使纳米金发生团聚, 导致纳米金的颜色从酒红色变为蓝色。由于金黄色葡萄球菌目标序列浓度的不同, 从而引起纳米金之间团聚的程度不同, 纳米金就会相应的呈现出不同的颜色变化, 这样就可达到可视化检测的目的。结果 在最优实验条件下, 本方法在检测金黄色葡萄球菌目标序列时, 浓度在1~1000 pmol/L范围内呈现良好的线性关系, 检出限为0.5 pmol/L; 检测金黄色葡萄球菌时, 线性范围为30~9800 CFU/mL, 检出限为25 CFU/mL。结论 通过特异性和加标回收实验, 证明本方法可以用于实际样品的检测。

A nano-gold labling-based visual detection method for Staphylococcus aureus

Objective To set up a visual detection method of Staphylococcus aureus based on the color-changing effect of AuNPs. Methods The DNA 1 and DNA 2 which were complementary with the target DNA of Staphylococcus aureus were connected to the surface of AuNPs. When the target sequence of Sta-phylococcus aureus appeared, the two short-chain DNAs hybridized to the target sequence, and the AuNPs became closer, then the color of AuNPs turned blue from wine red. The different concentrations of target se-quence caused different degrees of aggregation between AuNPs, and the AuNPs accordingly showed different colors . Results Under optimal conditions, the correlation between concentration of target sequence of Staphylococcus aureus and A700/A525 was observed to be linear within the range of 1~1000 pmol/L, and the detection limit of the proposed method was 0.5 pmol/L. The correlation between concentration of Staphylococcus aureus and A700/A525 was observed to be linear within the range of 30~9800 CFU/mL, and the detection limit of the proposed method was 25 CFU/mL. Conclusion The specificity and spiked recovery experiments proved that this developed method could be used for detection of actual sample.