Pegylated Polyurethane Nanoparticles as Support for a Biosensor Construction based on Peroxidase Extracted from Pine Kernel (Araucaria Angustifolia)

In the present work, we have used polyurethane nanoparticles to support a biological material to construct a biosensor. The device is based on pine kernel (Araucaria angustifolia) tissue homogenate as a source of peroxidase, developed for the determination of dopamine in pharmaceutical products. The biosensor was constructed by the immobilization of peroxidase on pegylated polyurethane nanoparticles and square-wave and cyclic voltammetry experiments were performed. The best analytical response was obtained for a 75:15:10 % (w/w/w) composition of graphite powder: Nujol: polyurethane nanoparticles containing 2.5 units of peroxidase/mg of carbon paste, 0.1 mol L−1 phosphate buffer solution (pH 6.5), 2.0×10−3 mol L−1 hydrogen peroxide, 80 mV pulse height and 60 Hz frequency. The analytical curve was linear for dopamine concentrations from 3.33×10−5 to 6.60×10-4 mol L−1 (r = 0.9994) and the regression equation was found to be ≜I = 14.38 + 27.47×103 [dopamine] with limit detection.