| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 867430 | Biosensors and Bioelectronics | 2012 | 5 Pages |
There has been an enormous demand for commercial label-free DNA sensors in a diverse range of fields including pre-emptive medicine, diagnostics, environmental monitoring, and food industry. Addressing the need for sensitive, selective and facile DNA sensors, we demonstrate a novel switch on/off sensor design that utilizes sandwich hybridization between photoluminescent anionic conjugated polyelectrolyte (CPE) bound captureprobe coated onto magnetic beads, target and the signaling probe. The hybridization-readout in our sensor was monitored by either fluorescence resonance energy transfer (FRET, switch-on) or superquenching (switch-off) depending on the type of signaling probe used. Moreover recent designs that utilize beads for sensing DNA have been limited towards using electrostatic interactions or intercalation of dyes to observe FRET. To our knowledge this is the first report of a switch on/off sensor utilizing either FRET or superquenching thus providing flexibility for future development of such rapid, facile and sensitive DNA sensors. The FRET-based sensor was investigated by optimizing the reaction parameters and selectivity. A low detection limit of 240 fmol in 2 mL of SSC buffer was achieved.
► To our knowledge we report the first integrated DNA sensor utilizing Forster resonance energy transfer (FRET) (turn-on) or superquenching (turn-off) for detection. ► The sensor design utilizes sandwich hybridization between photoluminescent conjugated polyelectrolyte (CPE) bound captureprobe coated onto magnetic beads, target and the signaling probe. ► The mode of hybridization readout – FRET or fluorescence quenching depends in a subtle way on the position of the Cy3 dye on signaling oligonucleotide (ODN) probe. ► The FRET-based sensor was investigated in detail and demonstrated good selectivity with non-complementary and mismatched ODNs. ► The reaction parameters were optimized and a sensitive detection limit of 240 fmol was observed for the FRET-based sensor.
