Current biosensors are designed to target and react to specific nucleic acid sequences or structural epitopes. These target-specific platforms require creation of new physical capture reagents when new organisms are targeted. An open-target approach to DNA microarray biosensing is proposed and substantiated using laboratory generated data. The microarray consisted of 12,900 25 bp oligonucleotide capture probes derived from a statistical model trained on randomly selected genomic segments of pathogenic prokaryotic organisms. Open-target detection of organisms was accomplished using a reference library of hybridization patterns for three test organisms whose DNA sequences were not included in the design of the microarray probes.