Highly sensitive Apt-LFA detection for Staphylococcus aureus based on multifunctional nanoenzyme
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 Fe3O4@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 10~100 000 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.