[Study of enzyme immunosensor immobilized by regenerated silk fibroin]

The author studies the enzyme immunosensor made up of graphite electrode and protein film of regenerated silk fibroin which is employed to immobilized antigen (rabbit IgG). IgG will be recognized and combined by antibody (goat-anti-rabbit IgG-HRP). After enlarging the signal of the combination of antigen and antibody by H2O2, the concentration of IgG is able to be measured by testing the electrode potential directly. The Enzyme Immunosensor is sensitive when measuring IgG and the detection limit of 1.2 x 10(-10) mol/L is found. It shows linear response over the concentration range of 4.1 x 10(-7)-1.2 x 10(-10) mol/L. Electrophoresis cuts down the time of antibody-antigen interaction from 90 min to 30 min. The response time is 15 s. Enzyme immunosensor with better stability and higher sensitivity can be used extensively in clinical diagnosis, medical and environmental studies, HLA molecular diagnosis and so on.