A microfluidic chip for measurement of biomolecules using a microbead-based quantum dot fluorescence assay

This paper describes a custom-designed microfluidic chip for sensitive detection of antibody using quantum dot fluorescence in a microbead-based assay. The microfluidic chip is designed to isolate a single microbead where the binding reaction of antibodies happens on the surface. The microfluidic chip is fabricated on a glass substrate using transparent silicone elastomer, PDMS, for easy access to monitoring and flexible gate operations to capture the single microbead. For antibody detection, a sequence of functionalized assay has been performed in the fabricated chip including: capturing of microbeads; antibody injection into a micro-chamber; quantum dot injection; and fluorescence detection. Various concentrations of antibody have been tested and have shown good agreement with correlated fluorescent intensities.