Microfluidic bioassay system based on microarrays of hydrogel sensing elements entrapping quantum dot-enzyme conjugates

► Microfluidic biosensor able to detect substrates of oxidase enzymes. ► Enzyme-quantum dot (QD) conjugates are entrapped within hydrogel microarrays. ► Hydrogel microarrays are fabricated within microchannels by photopatterning. ► The reaction between oxidase and substrate produce H2O2, which quench the QDs. ► Glucose and alcohol are detected using glucose oxidase and alcohol oxidase.