基于多功能纳米酶的高灵敏金黄色葡萄球菌Apt-LFA检测方法

Highly sensitive Apt-LFA detection for Staphylococcus aureus based on multifunctional nanoenzyme

侧流层析分析(lateral flow assay,LFA)具有操作简单、成本低等优点,在致病菌检测领域应用前景广阔,但以胶体金为标记的LFA比色分析灵敏度较低。基于此,通过合成万古霉素修饰的Fe_(3)O_(4)@MOF@PtPd作为磁分离/纳米酶双功能信号探针,并与金黄色葡萄球菌适配体(aptamer,Apt)相结合,实现了夹心模式的LFA检测。在最优条件下,该LFA传感器可以实现对金黄色葡萄球菌的检测,其线性范围为10~100000 CFU/mL,检测限为2 CFU/mL;该试纸条对牛奶中所添加金黄色葡萄球菌的所得回收率为96.9%~103.4%。研究结果反映出该LFA传感器具有灵敏度高、操作简便的优点;同时,其具有通用性,仅通过更换适配体就能应用于其他革兰氏阳性菌的检测。

Lateral flow assay(LFA)has a broad application prospect in the detection of pathogenic bacteria due to its advantages of simple operation and low cost,but colorimetric analysis of LFA labeled with colloidal gold is still faced with low sensitivity.In this work,vancomycin-modified Fe_(3)O_(4)@MOF@PtPd was synthesized and used as a magnetic separation/nanoenzyme bifunctional signal probe.It was combined with aptamer(Apt)of Staphylococcus aureus to achieve sandwich mode LFA detection.Under optimal conditions,the LFA sensor can detect Staphylococcus aureus with a linear range of 10~100000 CFU/mL and a detection limit of 2 CFU/mL.The LFA strips gave recovery rates of 96.9%~103.4%for Staphylococcus aureus spiked in milk.The results showed that the LFA sensor has the advantages of high sensitivity and simple operation.At the same time,it is versatile and can be applied to the detection of other gram-positive bacteria only by changing the aptamer.