The Research Of Micro Enzyme Immunosensor For Rapid Detection Of Salmonella Pullorum And Salmonella Gallinarum

Fowl typhoid and Pullorum disease are usually caused by the infection of Salmonella pullorum and Salmonella gallinarum, they have became a significant risk factor for food-borne disease because of its high morbidity and mortality and huge hazard for fowl. Now the livestock industry has give priority to the prevention of food-borne disease. It’s necessary to supervise and control the contamination caused by S. pullorum and S. gallinarum quickly and ecactly in time.Electrochemical enzyme immunosensor is a way combined with electrochemical skill and enzyme immune skill, it has many advertisements such as high specificity, effective and works easily which turns out a broad potential applications. The research on electrochemical enzyme immunosensor is on the active both here and abroad, mainly on the rapid detection of food-borne pathogenic bacteria, virus and toxin, barely on the animal medicine. Improving the deficiencies of electrochemical enzyme immunosensor to develop a new rapid immunosensors by using innovative materials such as graphene, Au-Nanoparticals is the hotspot of research now. The research tasks conducted in this paper were described as follows:1. A disposable direct enzymatic immunosensor for rapid detection of S. pullorum&S. gallinarum based on electrochemical codeposition of ERGO and AuNPsIn order to prepare a new electrochemical enzyme immunosensor which is high of specificity and stability for rapid detection of S. pullorum&S. gallinarum, ERGO-AuNPs electrode was fabricated by electrochemical codeposition of ERGO and AuNPs which electricity and biology has efficiently been improved to structure a novel immunosensor for S. pullorum&S. gallinarum. Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) were carried out to characterize the electrochemical properties of different modified electrodes as thionine a probe. Under the optimal conditions the research indicates that the enzyme immunosensor possesses a favorable liner in the concentration range of103-109cfu/mL of S. pullorum&S. gallinarum, with a low detection limit of1.6x102cfu/mL (S/N=3). The composite membranes formed by codeposition of ERGO and AuNPs efficiently promote the delivery of electron on screen-printed carbon electrode surface, enhance the response signals and improve the sensitivity, specificity and stability (remained94.48%of its original signal after storage at4℃for30d) of immunosensor. It turns out that the complex formed by codeposition of ERGO and AuNPs has a good result, which is contribute to the further research. 2. A disposable sandwich enzymatic immunosensor for rapid detection of S. pullorum&S. gallinarum based on electrochemical codeposition of ERGO and AuNPsIn order to amplify and improve the signal, a novel rapid electrochemical enzyme immunosensor for detection of S. pullorum&S. gallinarum was developed. ERGO-AuNPs electrode was fabricated by electrochemical codeposition of ERGO and AuNPs which electricity and biology has efficiently been improved to structure a novel immunosensor for S. pullorum&S. gallinarum via double antibody sandwich method. The Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) were carried out to characterize the electrochemical properties of different modified electrodes as thionine a probe. Under the optimal conditions the research indicates that the enzyme immunosensor possesses a favorable liner in the concentration range of103-109cfu/mL of S. pullorum&S. gallinarum, with a low detection limit of1.2×102cfu/mL (S/N=3). The composite membranes formed by codeposition of ERGO and AuNPs efficiently promote the delivery of electron on screen-printed carbon electrode surface, enhance the response signals and improve the sensitivity, specificity and stability (remained97.14%of its original signal after storage at4℃for30d) of immunosensor. This novel method not only could be applied for S. pullorum&S. gallinarum, but proved as a basic model of other immunosensors for pathogenic microorganism and toxic substances detections. 3. A disposable indirect enzymatic immunosensor for rapid detection of S. pullorum&S. gallinarum based on electrochemical codeposition of ERGO and AuNPsIn order to prepare a new electrochemical enzyme immunosensor for detection of S. pullorum&S. gallinarum, ERGO-AuNPs electrode was fabricated as the biological carrier by electrochemical codeposition of ERGO and AuNPs to structure a novel immunosensor for S. pullorum&S. gallinarum through the indirect method. The Cyclic Voltaminetry (CV) and Electrochemical Impedance Spectroscopy (EIS) were carried out to characterize the electrochemical properties of different modified electrodes as thionine a probe. Under the optimal conditions the research indicates that the enzyme immunosensor possesses a favorable liner in the concentration range of103-109cfu/mL of S. pullorum&S. gallinarum, with a low detection limit of5.9×102cfu/mL (S/N=3). The composite membranes formed by codeposition of ERGO and AuNPs efficiently promote the delivery of electron on screen-printed carbon electrode surface, enhance the response signals and improve the sensitivity, specificity and stability (remained93.36%of its original signal after storage at4℃for30d) of immunosensor. It turns out that the complex formed by codeposition of ERGO and AuNPs has a good result, which is contribute to the further research.