Abstract: A rapid assay for E.Coli 0157∶H7 has been developed by using an integrated portable SpreetaTMSPR biosensor. Avidinbiotin system was used to guarantee the detection accuracy. The assay is based on the adsorption of E.Coli 0157∶H7 antibody. Using the sandwich method of primary antibodyantigensecondary antibody to increase the antigen mass and to amplify the E.Coli 0157∶H7 detection signal. Adopting immunity colloid gold as secondary antibody, the antigen mass was significantly increased and detection signal was further enhanced. At the same time, the assay has prolonged the combination time of colloid gold antibody and microbe, then the detection signal was amplified further, thereby the detection limit has been extended from 106 cfu/mL to 101 cfu/mL.

Key words: instrument detection, immune colloid gold, SPR biosensor, microbe, detection limit