Bisphenol-A (BPA) is a monomer commonly used in the production of epoxy
resins, plastic bottles and dental filling materials. Due to its chemical
structure, BPA and its derivates shows activity similar to the endocrine
hormones. It can bind to estrogen receptors and cause neurological
disturbances, even at low doses. Therefore, it is important to determine BPA
and its derivatives quickly and sensitively at low concentrations. In this
study, a single amperometric tyrosinase enzyme biosensor was designed for
the determination of the amount of BPA, BPF (Bisphenol F) and BPS (Bisphenol
S) monomers. Tyrosinase was immobilized onto a modified carbon paste
electrode by cross-linking with glutaraldehyde. The amount of BPA (BPS and
BPF) was determined directly on the reduction of quinone compound that
released as a result of the enzymatic reaction at -0.15V. Km(app) value of
the designed biosensor for BPA was found 0.00067 ?M, the linear operating
range was 0.001-0.005 ?M (a) and 0.03-0.1 ?M (b) and the lower detection
limit was found 1 nM for each monomer. It is clear that designed biosensor
is enable the fast, efficient and precise determination of BPA and its
derivatives released from materials used in dental materials.