Study On AFP Immunosensor With Silk Fibroin Sensitive Membrane

To explore the application of biosensors in clinical determinations, the tumor antigen AFP in human serum is detected by direct potentiometric method using our self-made membrane electrodes. In comparison with the results of the highly cost electrochemiluminescence method, it is expected to assess AFP exactly and simply. All the experiments can also provide a number ofdata for our future research work. A kind of new biomaterials------silk fibroin protein was taken as the carrier of electrode sensitive membrane and a kind of self-made membrane electrode was used as working electrode, as well as reference electrode. The detection limit for AFP is ng/ml order and the linearity range is 10-400ng/ml. This method with no label, no contamination is simple, rapid and convenient enough for application. In our work, the silk fibroin was dissolved by the neutral salt (CaCl2) and formed a kind of protein membrane on plastic mold. This membrane with the excellent properties in diffusivity of materials, mechanical strength and handling is good for immobilizing biomolecular stuff. The stuff immobilized on the surface of the membrane still has high activity and stability. It can be stored for long time. Moreover, the electrode system we have taken here is considerably stable. Experimental results show that the potential immunosensor has good reproducibility.