Construction Of Electrochemical Biosensor Based On Au@PB NPs And Its Application In Glucose Detection

As the most widely distributed and most important monosaccharide in nature,glucose has very important research value and application prospect in the fields of food industry,medicine and health,biotechnology and so on.With the progress of science and technology and the continuous development of detection methods,a variety of glucose detection methods have emerged,such as spectrophotometry,rotation photometry,gas chromatography,high performance liquid chromatography,biosensor and surface plasmon resonance and so on.These detection methods have their own advantages and disadvantages and have different application value in different detection scenes.Among them,biosensor has attracted wide attention in recent years,which is widely used in glucose detection and analysis because of its high selectivity,simple operation,low cost and fast response.At present,glucose biosensor mainly includes enzyme-based glucose biosensor and non-enzymatic glucose biosensor.In the enzyme-based glucose biosensor,how to better immobilize the enzyme on the electrode surface and have a faster electron transfer rate,the researchers explored a variety of electron transfer mediators to accelerate the electron transfer efficiency in the catalytic reaction.Prussian blue(PB)nanomaterials,as the electron transfer mediators of the second generation biosensors,show good redox properties in the electrochemical process.It is a widely used electronic medium in enzyme-based biosensors.With the development of nanomaterials,composite nanomaterials show more excellent physical and chemical properties than single nanomaterials,and can better improve the performance of the sensor.Therefore,in our thesis,we studied the performance of flexible glucose biosensor based on self-catalytic synthesis size controllable Gold@Prussian Blue nanoparticals(Au@PB NPs)in H₂O₂ and glucose detection and applied it to the detection of real samples.The research content mainly includes three parts:(1)Gold nanoparticals(Au NPs)catalyzes the synthesis of core-shell structure of PB precursor with controllable size Au@PB NPs,is proved to have high stability,good water solubility and biocompatibility by characterization,and it is found that the thickness of PB layer can be controlled by the size of Au NPs.Electrochemical tests show that Au NPs can promote the electron transfer efficiency of Au@PB NPs on the electrode surface and show good sensing performance in H₂O₂ catalysis,which can be further used in the preparation of glucose biosensor.(2)Au@PB NPs with controllable size was immobilized on the graphene paper with ultra-high specific surface area,and the Au@PB NPs-r GO electrode with excellent electrocatalytic performance was prepared.The high sensitivity(H₂O₂:77.42?A m M cm^-2;glucose:75?A m M cm^-2)and the detection limit(H₂O₂:0.27?M;Glucose:1.02?M)were verified in H₂O₂ and glucose sensors and applied to the detection and analysis of real samples(beer).The glucose in beer was calculated to be 5.83g/L,and the effects of interfering substances(V_B1,V_B6,AA)on the biosensor were analyzed.The results show that the glucose biosensor has good specificity and sensitivity.(3)We mixed the synthesized core-shell Au@PB NPs into carbon ink using screen printing technique prepared glucose biosensor on polyethylene terephthalate(PET)flexible substrate,and analyzed the catalytic performance of Au@PB NPs-SPE for the detection of H₂O₂and glucose(H₂O₂:301.5?A m M^-1 cm^-2;Glucose:29.3?A m M^-1 cm^-2)and applied to the detection and analysis of real samples(beer).The results show that the content of glucose in beer is 4.39g/L,which is basically consistent with the results measured by Au@PB NPs-r GO sensor.The interfering substances(V_B1,V_B6,AA)in the samples were also analyzed,and it was proved that the SPE biosensor had good stability and specificity in the actual sample detection and analysis.