Development of analytic microdevices for the detection of phenol using polymer hydrogel particles containing enzyme–QD conjugates

We present the fabrication of a microdevice for the detection of phenol by combining microfluidic channels and poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogel microparticles containing tyrosinase–quantum dot conjugates. PHEMA hydrogel microparticles containing conjugates of enzyme (tyrosinase) and quantum dot (QD) were prepared by dispersion photopolymerization and entrapped within a microfilter-incorporated reaction chamber in a microfluidic channel. The fluorescence change, due to the fluorescence quenching effect caused by the enzyme reaction between phenol and tyrosinase, was used to detect phenol. The fluorescence intensity of PHEMA hydrogel microparticles containing tyrosinase–QD conjugates at 585 nm decreased with phenol concentration. In conclusion, the microfluidic channels fabricated in this study entrapping PHEMA hydrogel microparticles containing enzyme–QD conjugates show the potential to be used as an analytic microdevice for the detection of phenol.