A microfluidic detection device is provided that includes a planar waveguide, or an ion-exchange planar waveguide, a microfluidic channel disposed on the planar waveguide, a light source, such as a laser, LED or incandescent light, directed through the planar waveguide, a labeled cell disposed in the microfluidic channel, where the labeled cell lies in an evanescent field extending from the planar waveguide, and a light detector disposed to receive light from the light source through the planar waveguide. The evanescent field interacts with the labeled cell, where the light through the planar waveguide is altered according to a presence of the labeled cell in the microfluidic channel.