Enzymatic Synthesis of Fluorescent Naphthol-Based Polymers

A fluorescent polymer of 2-naphthol is prepared using the oxidative enzyme horseradish peroxidase encapsulated in the microstructured system of AOT/isooctane reversed micelles. The monomer, being amphiphilic, partitions to the oil−water interface with the hydroxyl moieties directed toward the microaqueous core. The enzyme is encapsulated in the water core. The precipitated polymer of naphthol has the morphology of single and interconnected microspheres and is soluble in a range of polar and nonpolar organic solvents. Poly(2-naphthol) shows a fluorescence characteristic of the naphthol chromophore and an additional well-resolved fluorescence attributed to an extended quinonoid structure attached to the polymer backbone. Further evidence of the quinonoid structure is obtained through UV, IR, and NMR spectroscopy. Characteristics of the synthesis and structure of poly(2-naphthol) are compared with those of a less fluorescent polymer, poly(4-ethylphenol).