Authors: S. Dubus, B. Le Droggof, J-F. Gravel, D. Boudreau and T. Veres
Affilation: Laval University, Canada
Pages: 225 - 228
Keywords: DNA-based biosensor, Magnetic Particles, Fluorescence, PCR-Free sensibility, on-site detection
DNA-based biosensor technologies for rapid, sensitive and affordable identification of genetic material are in constant evolution and show great potential in various fields. The ability for such methods to be used directly at point-of-care settings or in the field by staff with no laboratory training is gaining in importance, especially in critical situations where answers are needed within a timeframe that is beyond the response time of PCRbased techniques. The new approach presented herein is based on the development of a microfluidic platform for the rapid and selective capture and pre-concentration of target nucleic acids on probe-functionalized magnetic beads using integrated microelectromagnetic traps, followed by real-time optical detection using a cationic biochromic polymer acting as transducer of the probe-target hybridization event. A systematic investigation was performed in terms of particle trapabilty in a micro fluidic flow environment under magnetic field and fluorescence signal as a function of bead size (ranging from 2.8 m to 500 nm). This investigation led to the design of an optimal, fully integrated analysis system (lab-on-a-chip): extraction, purification, identification and detection of target DNA sequences. This technique allows the detection of less than 200 bio-threat-specific DNA target copies in less than one hour and without any chemical reaction. This novel and simple technology should therefore enable on-site, rapid detection and identification of potential bioweapons for first responders and public health providers.