Assay sensitivity is one of the most important factors to consider when developing microarray-based biosensors for the detection of pathogens. In fluorescence based detection assays, signal intensity is determined by the amount of label that can be localized at the reaction site. Increasing microarray feature signal intensity (and thus assay sensitivity) can be accomplished by increasing the signal output per binding event. This is traditionally done by increasing the number of fluorophores attached to the antibody or DNA either directly or using a biotin-avidin (or equivalent) bridge. However,lack of control over the fluorophore to fluorophore distance leads to significant quenching via resonance energy transfer. In this presentation we show how a mutant of a cow pea mosaic virus (CPMV) has been used to improve the detection sensitivity of a DNA array sensor. We present results on the detection of six Vibrio cholerae toxin encoding genes from a single genomic copy. These studies have shown that the modified CPMV provides not only enhancement in detection sensitivity, but also a greatly simplified protocol. The other attributes of this approach are reduced false positives,low background, and reduced time as well as cost.