Magnetic modulation biosensing (MMB) system is experimentally demonstrated for rapid and homogeneous detection of the Ibaraki virus NS3 cDNA. A novel fluorescent resonance energy transfer (FRET)-based probe discriminates the target DNA from the control. When detection is made, the FRET-based probe is cleaved using Taq-polymerase activity and fluorescent light is produced. The biotinylated probes are attached to streptavidin-coupled superparamagnetic beads and are maneuvered into oscillatory motion by applying an alternating magnetic field gradient through two electromagnetic poles. The beads are condensed into the detection area and their movement in and out the orthogonal laser beam produces a periodic fluorescent signal that is demodulated using synchronous detection. 1.9 pM of the Ibaraki virus NS3 cDNA was detected in homogeneous solution within 18 min without separation or washing steps.
Bibliographical noteFunding Information:
The authors wish to thank the Ishaia Horowitz Fund for financial support, Dr. Alex Barbul, Dr. Konstantin Bogdanov, Dr. Nihay Laham-Karam, and Dr. Ophir Riss, for their assistance in the measurements and for fruitful discussions.
- DNA detection
- Fluorescence and luminescence
- Ibaraki virus
- Magnetic beads
- Magnetic modulation
- Magnetic nanoparticles