an optical biosensor has a first enclosure with a pathogen recognition surface , including a planar optical waveguide and grating located in the first enclosure . an aperture is in the first enclosure for insertion of sample to be investigated to a position in close proximity to the pathogen recognition surface . a laser in the first enclosure includes means for aligning and means for modulating the laser , the laser having its light output directed toward said grating . detection means are located in the first enclosure and in optical communication with the pathogen recognition surface for detecting pathogens after interrogation by the laser light and outputting the detection . electronic means is located in the first enclosure and receives the detection for processing the detection and outputting information on the detection , and an electrical power supply is located in the first enclosure for supplying power to the laser , the detection means and the electronic means .