We have developed a novel microfluidic device with microbeads array for sensitive detection and genotyping of human papillomavirus (HPV). Polystyrene microbeads were modified with primary DNA probes and electron-rich proteins and docked in the microfluidic channels in an array format. Gold nanoparticles were functionalized with horseradish peroxidase (HRP) and secondary DNA probes. Hybridization of target sequences with the DNA probes conjugated the enzyme-functionalized Au nanoparticles to the surface of microbeads, where the oxidation of biotin–tyramine by hydrogen peroxide resulted in the deposition of multiple biotin moieties onto the surface of beads, catalyzed by the immobilized electron rich proteins. Streptavidin-labeled quantum dots were then allowed to bind to the deposited biotin moieties and further amplifies the signal, leading to enhanced sensitivity with the limit of detection for specific HPV sequences at 1 fmol/L (S/R>3). The microfluidic chip-based assay was three magnitudes higher in sensitivity than that of an off-chip test. The protocol could discriminate and genotype 10 copies/L HPV genomic DNA in combination with PCR.

Biography:
Prof. Yang obtained his PhD from University of Toronto, Canada and received postdoctoral training in the Scripps Research Institute in USA. He is currently the Head of Department of Biomedical Sciences, and Yeung Kin-Man Chair Professor of Biomedical Sciences in City University of Hong Kong. The research interest of Yangʼs group focuses on the development of biochip technology and nanotechnology for molecular diagnostics and therapeutic applications. Prof. Yang has published over 280 peer-reviewed scientific papers and received 23 USA/China patents.