Assessment of pathogenic bacteria using periodic actuationElectronic supplementary information (ESI) available: Assessment of cell concentration and capture using fluorescence and an animation of the magnetic field gradient synchronized with a movie showing the oscillating magnetic beads in real time. See DOI: 10.1039/c3lc50411e

A new analytical platform for the assessment of pathogenic bacteria is presented. It is based on a robust technology which is able to amplify the signal to noise ratio providing fast and sensitive detection of target pathogenic bacteria. The system uses a custom made AC electrical impedance analyser to measure, using a lab on a chip platform, the oscillations of magnetically labelled analytes when applying a periodic magnetic field. The concentration of pathogenic Escherichia coli O157:H7 chosen as bacterial model was determined based on the amplitude of the electrical impedance oscillations at a selected AC frequency. The analytical platform provides a limit of detection of 10 2 cells ml 1 , has a fast analysis time, and is amenable for the detection of other target cells. The system has simple design suitable for portability and automated operation. We report the fast, sensitive detection of target bacteria using electrical sensing of oscillating clusters comprising target cells affinity captured by magnetic beads.