Enzymatically generated polyphenols as array-based metal-ion sensors Original Research Article

Phenolic polymers containing fluorescent reporter molecules were prepared via soybean hull peroxidase (SBP) catalysis, and used as metal-based sensor components. Specifically, we generated a variety of phenolic homopolymers containing p-cresol, p-phenylphenol, or p-methoxyphenol containing one of the two fluorophores: fluorescein and calcein. The fluorescence of the resulting polyphenols was dependent on the presence of metal ions, including Cu2+, Fe2+, Zn2+, Mn2+, and Fe3+. The fluorescence response was dependent on both, the metal ion and the phenolic monomer used in polyphenol synthesis, indicating that significant control over the selectivity and sensitivity of metal sensing can be achieved by varying the components that comprise the phenolic polymer. In some cases, metal-ion concentrations as low as 10 μM can be analyzed. The broad reactivity of SBP toward phenolic monomers enables the use of a wide array of structures and chemistries that can assist in metal-ion detection.