Enzyme-based electrodes for environmental monitoring applications

A biosensor is described for the detection of phenolic compounds in water. The biosensor was fabricated by immobilizing tyrosinase in a thin layer of Eastman AQ polymer on the surface of a screen-printed electrode. The sensitivity of the biosensor is stable for 2 months at room temperature. The biosensor exhibited good sensitivity to seven of the nine phenolic compounds tested. The limit of detection (LOD) of the biosensor to phenol, catechol, 4-ethylphenol, and p-cresol was 1.5 μg/l, 0.7 μg/l, 1.4 μg/l, and 3.52 μg/l, respectively. The average precision for these four phenols was found to be approximately 7% relative standard deviation (RSD). The correlation coefficient between the biosensor and U. S. EPA Method 420.1 was found to be 0.96 when samples of water from seven areas of the United States were spiked with phenol concentrations ranging from 0.25 to 2 mg/l and analyzed with both methods. The biosensor has the potential to reduce the sampling time and cost of analyzing phenolic compounds in the field. © 1998 John Wiley & Sons, Inc. Field Analyt Chem Technol 2: 351–361, 1998