Array biosensor for detection of biohazards

A fluorescence-based biosensor has been developed for simultaneous analysis of multiple samples for multiple biohazardous agents. A patterned array of antibodies immobilized on the surface of a planar waveguide is used to cap ture antigen present in samples; bound analyte is then quantified by means of fluorescent tracer antibodies. Upon excitation of the fluorophore by a s mall diode laser, a CCD camera detects the pattern of fluorescent antibody: antigen complexes on the waveguide surface. Image analysis software correla tes the position of fluorescent signals with the identity of the analyte. T his array biosensor has been used to detect toxins, toxoids, and killed or non-pathogenic (vaccine) strains of pathogenic bacteria. Limits of detectio n in the mid-ng/ml range (toxins and toxoids) and in the 10(3)-10(6) cfu/ml range (bacterial analytes) were achieved with a facile 14-min off-line ass ay. In addition, a fluidics and imaging system has been developed which all ows automated detection of staphylococcal enterotoxin B (SEB) in the low ng /ml range. (C) 2000 Elsevier Science S.A. All rights reserved.