Detection of Staphylococcus Aureus in Different Liquid Medium Using Wireless Magnetoelastic Sensor / 分析化学

ABSTRACT

A magnetoelastic Staphylococcus aureus (S.aureus) wireless sensor was fabricated to detect S.aureus in different liquid medium.After 0.2 mL bacteria with proper concentration was taken into the tes ting cuvette containing 2 mL liquid medium, the resonance frequency of magnetoelastic sensor changed with the bacteria growth.Via changing the concentration of beef extract and peptone, sensor had the most frequen cy response in culture medium CM2-2 incubated with 2 × 10~5 cells/mL S.aureus.The results indicated that this sensor can be used to determine S.aureus concentrations of 3 × 10~3 to 2×10~7 cells/mL in culture medium and 10~4 to 10~7 cells/mL in milk, with the detection limits of 10~3 cells/mL and 104 cells/mL, respectively.The sensor frequency shift was correlated to the logarithmic value of the S.aureus concentration, and the correlation coefficient was 0.98 in milk and 0.99 in culture medium.