3. EBAT/ Eurasia Biochemical Approaches & Technologies Congress, Antalya, Türkiye, 4 - 07 Kasım 2021, ss.154
Bisphenol
A, 2,2-Bis-4-hydroxyphenyl-propane, (BPA) is a monomer commonly used in the
production of epoxy resins and polycarbonate plastics. BPA plastics are
frequently used in cups, home food containers and dental filling materials. Due
to its chemical structure, BPA shows activity similar to the endocrine hormones
estradiol and diethylstilbestrol1. BPA and its derivatives can bind to estrogen receptors
and cause neurological disturbances, even at low doses, where it acts similar
to estrogen. Therefore, it is important to determine BPA and its
derivatives quickly and sensitively at low concentrations1.
In this
study, the amount of BPA in various materials used in daily life was determined
with an amperometric tyrosinase biosensor. Commercial Fe3O4
nanoparticles were used to modify carbon paste electrode (MCPE). Tyrosinase was immobilized on MCPE by
cross-linking method with glutaraldehyde. BPA is oxidized to p-bisbenzoquinone
by an enzymatic reaction catalyzed by tyrosinase in the presence of oxygen. BPA
was quantified by measuring the electrochemical reduction of the
p-bisbenzoquinone compound formed as a result of the enzymatic reaction at -0.15
V. Then, the optimal working conditions necessary for the BPA biosensor were
investigated and the linear operating range of the biosensor was determined. In order to determine the optimum operating conditions
of the biosensor, the efect of pH and temperature was investigated. Optimum pH and temperature were found to be 5.0 and 40 oC,
respectively. The storage stability and application
stability of the biosensor were also studied. Several possible interfering substances’
effects on the BPA biosensor were investigated. The developed biosensor was
tested in determinations of BPA amount in a real sample.