A spatially addressable bead-based biosensor for simple and rapid DNA detection

A simple glass-polymer-based biosensor that allows arrays of beads to be immobilized, separated and identified without any prior encoding is developed. To do so, distinct bead types that are conjugated with different oligonucleotide probes are sequentially spotted onto a polymeric matrix (or gel pad) on the surface of the device. The spotted beads are firmly immobilized to the gel pad, acquiring spatial codes that allow them to be identified. Throughput is enhanced by spotting different bead types onto hundreds of different gel pads. The bead-based biosensor was applied for the DNA-based detection of 10 model bacterial species and two single-nucleotide polymorphisms, and based on passive hybridization the final signals are obtained with single-mismatch specificity within 10 min.