Study On Potentiometric Immunosensor Based On Gold Coated Magnetic Nanoparticles

Antibody immobilization on the solid surface is the pivotal process in the successful building of the immune sensors, and the method of immobilization would seriously affect the antibody-antigen reaction on the converter surface. In recent years, nanotechnology is widely used in biosensor research. The use of noble metal nanoparticles (Au, Ag, Pt), carbon nanomaterials, magnetic nanomaterials and self-assembled monolayer immunosensors has become the hot topic in biosensors field.This paper studies the applications of gold-coated Prussian blue nanoparticles, the fixed orientation of protein A antibody and the 4-MBA self-assembled monolayers in the potentiometric IgG immunosensors. Experimental results show that the gold-coated Prussian blue nanoparticles is an ideal immunosensor material; Oriented immobilization of antibody protein A can further improve the sensitivity of immunosensor; The hydrogen bonds between the 4-MBA molecules on the membrane surface can affect the performance of the immunosensor.(1).Prussian blue and gold coated magnetic Preparation and potentiometric immunosensor applicationMagnetic Prussian Blue (MPB) using iron oxide nanoparticles synthesized novel magnetic nano-materials.The sheep anti-mouse attached to the magnetic surface of the carbon paste electrode made of Ab/Au@ Fe3O4/Au@ PB/MCPE immunosensor. The sensor used in the determination of mouse IgG, Response to potential and the logarithm of antigen concentration was linear. The linear range of potential for 2x10-5～1x104ng/ml, with a detection limit of 3.1x10-44ng/ml.y=-22.89x-122.9,sensitivity of antigen detection, This modified electrode method is simple, low cost, both responsive, selectivity, stability and other characteristics. Detection of different proteins can be constructed for different sensors for a wide range of very good value. (2). Study on potentiometric immunosensor based on Immobilization of antibodyBy Au@ Fe3O4/Au@ MPB/MCPE surface self-assembled protein A goat anti-mouse IgG directed to the fixed magnetic carbon paste electrode surface. The linear range of potential for2.0 x 10-5～1.0x104 ng/ml, with a detection limit as low as 2.5x 10-4ng/ml, y=-39.89x-204.41 sensitivity of the sensor, response time was 6 min, Preparation of this sensor is simple and has good selectivity and stability.(3)4-MBA from intermolecular hydrogen bonding on the membrane surface properties of the immune sensorsFirst, gold electrode (Au) were prepared from the 4-mercapto benzoic Acid self- assembled monolayers (4-MBA SAM), and then was fixed by coupling antibodies (Ab), prepared by an immune sensor (Ab/4-MBA SAM/Au). Prepared under different pH examined the 4-MBA SAM or mixed thiol SAM on Ab/4-MBA SAM/Au performance. The results show that,4-MBA SAM intermolecular hydrogen bonding had been destroyed when pH was 3.The Ab/4-MBA/Au was prepared under the optimum acidity (A cetate buffer solution at pH 3.0). The linear range of potential for 4x10-4～1x104 ng/ml, with a detection limit of 3.3x10-4ng/ml.The response time was 8 min.The sensor exhibited high sensitivity was 6.04. In the pH 3 conditions that could inhibit 4-MBA from the group of hydrogen bonds between the membrane surface molecules produced beneficial Ab immobilized on the Au.