The Preparation Of Novel Electrochemical Biosensors

As all know,communication between proteins in living organisms plays a vital role in many physiological systems.For this reason, the signal transfer from protein to protein has stimulated many researchers to construct bio-sensors for the protein-to-protein electron transfer study. In the theses, we have studied the modified electrode based on the multi-protein and developed several novel biosensors.And we have also developed servral novel electrochemical biosensor for thrombin detection based on aptamer-modified electrode.We obtained some new results in following aspects:1.A novel thrombin sensor based on poly(vinylferrocenium) modified electrode was developed. In this part, we have studied the efffects of the supporting electrolyte, deposition time and pH of the buffer solution on thrombin detection in detailed. The sensor used on the label-freel aptamer and the polymer film stability, high sensitivity, the response signal strength and simple operation.2.A novel thrombin sensor based on aptamer modified gold nanoparticles.We have studied the electrode activation time, thrombin incubation time, incubation temperature, incubation solution effects of the modified electrode. We detect the thrombin through the reduction signal of gold nanoparticles.The sensor is simple, rapid, strong response signal, and can specifically detect thrombin. The sensor further development is expected to use in the disease diagnosis and treatment in real life.3.The electron transfer in a co-immobilized cytochrome c and horseradish peroxidase film. Although these two proteins are not sure whether existence cooperation in vivo, but we can through this research to analogize the electronic transmission of the mixed proteins.Experimental results show that the electron transfer rate constant of the mixed protein modified electrode is bigger than that value of the single protein modified electrode. This results shows that the mixed protein-modified electrode has significantly enhanced the electron transfer between protein and electrode.The multi-protein modified could be used for H2O2 and 02 detection.4. The GOD-Cyt.c mixed protein modified electrode assembled by layer-by-layer was investigated. The results shows that the mixed protein-modified electrode has significantly enhanced the electron transfer between GOD-Cyt.c modified electrode and solution. Herein, Cyt.c not only provides a good biological micro-environment, but also provides a good electronic transmission channel for GOD electron transfer between solution and electrode.