MEMS based impedance biosensor for rapid detection of low concentrations of foodborne pathogens

摘要

An impedance based MEMS biosensor for detection of Escherichia coli O157:H7 in food products was designed, fabricated and tested. The device was especially designed with regions for focusing the E.coli cells into the centerline of the microchannel, trapping that surrounds the detection electrode to confine and facilitate the contact and binding of E.coli antigens with E.coli antibody immobilized on the detection electrodes. The devices were tested with and without applying AC signal on the focusing electrodes. The results demonstrate the addition of the focusing capability has increased the strength of the measured signal by a factor of 9, and high sensitivity of 13 cell/ml and detection time of 30 minutes which is significantly quicker than traditional bacterial culture, PCR and ELISA based detection.