Fig 1. CV current measurement with a variety of NTproBNP concentration

Results and Discussion

The NTproBNP of diverse concentrations (10 ng/ml, 10 μg/ml) in PBS was applied and Figure 1 showed the results.The CV current valueswere 21.07μA, 37.65μA, at the concentrations, respectively, albeit no cyclic voltammetric responses were detected in PBS. The result indicates that the successful immobilization of antibodies onto the gold surface of the channel and oxidation peak currents attributed to the two-electron oxidation of PAP to PQI are dependent on immnoreactions and enzyme-substrate interactions.

In this study, a new strategy for effective immobilization ofantibodies and sensitivity enhancement in the development of an electrochemical biosensor is presented. The proposed strategy entails directlycoupling antibodies onto gold chip surfaces and employinggenetically engineered GBP-ProG fusion proteins as a novelcrosslinker. Experimental results demonstrated that the GBP-ProGproteins were successfully direct-immobilized onto immunochip viathe GBP domain, and simple and oriented binding of antibodiescould be achieved through the ProG portion of the layeredGBP-ProG without any additional chemical treatment. Theseresults provide a simple and effective approach for the fabricationof sensitive immunosensor. The electrochemical biosensor developedherein also could be used for monitoring heart failure patients.