Highly sensitive detection of L.monocytogenes using an electrochemical biosensor based on Si@MB/AuNPs modified glassy carbon electrode

L. monocytogenes (L. m) is one of the most common causes of foodborne diseases. To enable timely monitoring of L. m contamination, a highly efficient and sensitive electrochemical biosensor was developed for the precise determination of L.m. The biosensor was prepared by sequentially modifying glassy carbon electrode (GCE) with silicon methylene blue (Si@MB), gold nanoparticles (AuNPs) and aptamer (Apt). Differential pulse voltammetry (DPV) was used to quantify L.m. This biosensor could be finished in 1.5 h, which significantly reduced the detection time. The resulting electrochemical biosensor achieved good linear (102-107 CFU/mL) and excellent detection limit of 2.6 CFU/mL. Moreover, the novel strategy has been successfully applied to actual samples, with the recoveries ranging from 84.7% to116.0% in lettuce and from 80.0% to 110% in fresh-cut fruit. This biosensor shows great potential application in monitoring bacterial food contamination and infectious diseases.