Development of phenol detecting biosensor using PEG hydrogel microparticles

In this study, a simple and sensitive detection method for phenols were investigated using poly(ethylene glycol) (PEG) hydrogel microarray entrapping quantum dot (QD) and tyrosinase enzyme. Hydrogel microarrays were fabricated by using photo-patterning methods, and size of resultant hydrogel micropattern was ranged from 10 to 300 ¿m. The enzymatic reaction used for the detection of phenol is the oxidation of phenolic compounds via tyrosinase. In such reaction, phenol is oxidized to o-quinone which is a classic electron accepting chemical that can quench the fluorescence of QDs. Accuracy of the system was verified by measurement of photoluminescence (PL) quenching in free solution state with different concentrations of phenol. The PL quenching of QDs was investigated by varying the molecular weight of PEG, and concentration of QDs and/or enzymes.