Novel tyrosinase-based bisphenol-A biosensor for the determination of bisphenol-A in bracket adhesive in orthodontics

A novel biosensor for the determination of Bisphenol-A has been developed in this study. For this purpose, a carbon paste electrode modified with poly(amidoamine)-salicylidenimine platinum(II) (PAMAM-Sal-Pt(II)) and the tyrosinase enzyme was prepared. BPA determination was based on the electrochemical reduction of an enzymatically produced quinone compound at - 0.15 V. Optimum working conditions for the prepared biosensor were investigated. The linear working range and detection limit were found to be 0.01 - 1.0 μM and 1 nM, respectively. The optimum pH value and working temperature were defined as 7.0 and 40 ℃, respectively. The reproducibility of the biosensor is very good. It was found that phenol, nitrophenol, urea, potassium nitrate, hexane, acetonitrile, and ethyl acetate do not interfere with the BPA determination. The prepared biosensor was used for the first time in dentistry for the determination of BPA in a resin-based composite material used as a bracket adhesive in orthodontics. (author)