The goal of this project is to construct a novel fusion protein of gold binding polypeptides (GBP)-protein G (ProG) to develop an electrochemical biosensor for rapid and simple diagnosis and monitoring heart failure.

DH5-alpha E. coli strain was transformed by a genetically modified recombinant vector coding GBP and ProG. The GBP-ProG fusion protein was derived from the strain with IPTG-induced expression and purified using the TALON metal affinity resin. The resulting GBP-ProG was directly self-immobilized onto gold surfaces via the GBP portion, followed by the oriented binding of antibodies onto the ProG domain targeting the Fc region of antibodies.

An electrochemical immunochip was fabricated through the GBP-ProG and gold patterned interdigitated array electrode. Antibody immobilization onto the gold surface of the electrode by the GBP-ProG was rapidly and simply achieved with proper antibody orientation. This immunochip could be used for diagnosis and monitoring of heart failure.