Enzymatic coupling of phenol vapors onto chitosan

Phenols are important industrial chemicals, and because they can be volatil e, also appear as air pollutants. We examined the potential of tyrosinase t o react with the volatile phenol p-cresol. Three lines of evidence support the conclusion that volatile phenols react with tyrosinase and are coupled (i.e., chemisorbed) onto chitosan films. First, phenol-trapping studies ind icated that p-cresol can be removed from vapors if the vapors are contacted with tyrosinase-coated chitosan films. Second, the ultraviolet absorbance of tyrosinase-coated chitosan films changes dramatically when they are cont acted with cresol-containing vapors, whereas control films are unaffected b y contacting with cresol vapors. Third, pressure measurements indicate that tyrosinase-coated chitosan films only react with cresol vapors if the oxyg en cosubstrate is present. Additional studies demonstrate the potential of tyrosinase-coated chitosan films/membranes for the detection and removal of phenol vapors. (C) 2001 John Wiley & Sons, Inc.