@article{article_246673, title={Magnetite Nanoparticles and Prussian Blue Modified Amperometric Biosensor for Lactic Acid Determination}, journal={Selcuk University Journal of Science Faculty}, volume={42}, pages={17–29}, year={2016}, author={Kaçar, Ceren and Öztürk, Funda and Erden, Pınar Esra and Kılıç, Esma}, keywords={Lactic acid, Amperometry, Enzyme electrode, Fe3O4 nanoparticles, Prussian blue}, abstract={Carbon paste electrode modified with lactate oxidase (LOx) enzyme, Fe3O4 nanoparticles and Prussian blue (PB) was investigated as amperometric biosensor for lactic acid. LOx was immobilized by cross-linking with glutaraldehyde (GA) and bovine serum albumin (BSA) into carbon paste matrix. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to investigate the electron transfer properties of bare and modified carbon paste electrodes. The parameters affecting the analytical performance of the enzyme electrode have been investigated in detail and optimized. The optimum response to lactic acid was obtained in 0.05 M phosphate buffer at pH 5.5 when polarized at +0.10 V vs. Ag/AgCl. The biosensor provides a linear response for lactic acid in the concentration range of 7.5×10-6-1.3×10-4 M with a detection limit of 5.9×10-7 M and correlation coefficient of 0.998. The effects of interferents, the operational and storage stabilities of the biosensor were also evaluated. The biosensor showed 5.4% loss in its initial activity after one week when stored at +4°C.}, number={1}, publisher={Selcuk University}