Quantum-Dot-Tagged Bioresponsive Hydrogel Suspension Array for Multiplex Label-Free DNA Detection

A novel hydrogel suspension array, which possesses the joint advantages of quantum-dot-encoded technology, bioresponsive hydrogels, and photonic crystal sensors with full multiplexing label-free DNA detection capability is developed. The microcarriers of the suspension array are quantum-dot-tagged DNA-responsive hydrogel photonic beads. In the case of label-free DNA detection, specific hybridization of target DNA and the crosslinked single-stranded DNA in the hydrogel grid will cause hydrogel shrinking, which can be detected as a corresponding blue shift in the Bragg diffraction peak position of the beads that can be used for quantitatively estimating the amount of target DNA. The results of the label-free DNA detection show that the suspension array has high selectivity and sensitivity with a detection limit of 10(-9) M. This method has the potential to provide low cost, miniaturization, and simple and real-time monitoring of hybridization reaction platforms for detecting genetic variations and sequencing genes.