The development of a metal clad leaky waveguide sensor for the detection of particles

A novel leaky waveguide device for the detection of particles has been developed and shown to be more sensitive than the currently used waveguide sensors. These metal clad leaky waveguide (MCLW) devices have been used as preliminary study on the feasibility for the detection of soluble proteins but can also be used for the detection of large particles such as bacteria, bacterial spores, yeasts and latex beads. A MCLW device has been fabricated to increase the overlap of the evanescent field extension from the sensor surface with the particles in the bulk solution of a flowing system, to place most of the entire volume of the particles within the evanescent field. Increasing the overlap of the evanescent field with the particles and permitting mode propagation along the direction of a flow for a few millimetres provides an effective interrogation approach for multi-particle detection in a single flow channel.