Desarrollo de superficies modificadas oro - anticuerpo anti-PSPB para su uso como biosensor en la detección de preñez bovina

Abstract

Due to big importance of early clinical diagnosis of pregnancy in cattle, the aim of this work was the development of an ampero- metric biosensor which enables protein quantification of pregnancy specific protein B in biological fluids. To achieve this goal Mercato Undecanoic Acid was immobilized on the gold surface, with anti-PSPB and Horseradish Peroxidase. The immobiliza- tion was verified by electrochemical and non electrochemical methods, such as cyclic voltammetry and contact angle measure-ments respectively.The electrochemical performance of the electrode was studied by cyclic voltammetry and constant potential amperometry, to establish the relationship between the change in cathode current (the quinone reduction potential) and the concentration of PSPB. Due to the formation of large antigen antibody complexes which limit the access of the enzyme’s specific substrate to its active site, the cathodic current would decrease as was observed.The developed gold - anti-PSPB - HRP electrode showed a lineal dependence on the concentration of PSPB at potential of -200 mV (vs Ag/AgCl), both by cyclic voltammetry and constant potential amperometry. Therefore this study could be use for the design of an amperometric biosensor which allows the detection of bovine pregnancy at the earlier stages.