Study On Detection Of Salmonella And Lipopolysaccharide In Food By Electrochemical Sensor Chip

In recent years,Salmonella caused foodborne illness and food pollution issues have received widespread attention around the world.All countries in the world attach great importance to the discovery of salmonella.Molecular printing technology detects bacteria targeted by the embedded membrane.This method has a strong specificity,high sensitivity,fast detection speed,low cost and strong strength,excellent detection of target bacteria.The technology that senses cells uses living cells as cognitive elements,Salmonella lipopolysaccharide detection based on the response of pathogenic bacteria to lipopolysaccharide virulence factor(LPS)to cell stimulation.This method can simulate the true effects of toxins on the body and has a high sensitivity.This article focuses on Salmonella.We select different materials for substrate research and build electrochemical chips of discovery with different properties,separate preparation of electrochemical blot sensor and electrochemical 3D cell sensor on the basis of the chip for detecting salmonella and lipopolysaccharide in food.Provide a new way to discover and research Salmonella.The content of the research is as follows:(1)Explore different substrate materials to prepare electrochemical discovery chips with different properties.The use of polyethylene terephthalate film and paper base(PET)as the base material,using wax spray printing,laser engraving and screen printing technology to prepare self-directed PET chips and paper chips.The hydrophilicity of the two detection chips shows how self-directed PET chip and paper chip have good hydrophilic properties.Under the effect of hydrophilicity,the PET chip has good self-management skills and can absorb the solution into the channel.The working area of the paper chips can absorb cell solution in the paper fiber,and the fiber structure provides a good 3D environment for cell culture;The self-directed PET chip feedback current for electrochemical detection is 42.93 ?A,and the paper chip feedback feedback current is 11.4?A,both chips have good electrical conductivity;The self-steering function of the PET chip and the paper chip function in cell culture were studied,PET chips have good self-directing capabilities and paper chips can provide a 3D culture environment for cells.Apply both prepared potatoes to the construction of the subsequent sensors.(2)Research on electrochemical bacterial blot sensing method for direct detection of Salmonella.Using pyrrole(Py)as a functional monomer and Salmonella as the model bacterium,the bacterial imprinted polymer(BIP)was prepared by electrolymerization on the self-directed PET screen printed electrode.The use of BIP as a recognizable element for building a electrochemical bacterial blot sensor,Through adsorption of target bacteria in BIP,direct Salmonella detection can be achieved.The sensor has a good linear relationship between the concentration of bacteria and the current peak value in the range 3.0×102?3.0×107CFU/mL.The linear equation is y=-1.83x+39.12,R2=0.9924,and the detection limit is 100 CFU/ml.(3)Research on the method of sensing electrochemical cells to detect Salmonella LPS and to indirectly assess Salmonella contamination in food.Electrochemical preparation with a step of polypyrrole(PPy)/graphene(GO)conductive film with good biocompatibility on printed electrodes of paper chip screen.The composition of RAW264.7 cells and sodium alginate hydrogen was added to the bottom of the paper fibers and fixed to the surface of the modified electrode to form a 3D cell culture system.Using RAW264.7 cells as identification elements to build an electrochemical sensor cell to achieve a very sensitive and rapid detection of Salmonella LPS.The sensor has a good linear relationship between the LPS concentration and the peak peak current in the concentration range of 1×10-2?3 ng/mL.The linear equation is y=0.56x+43.64,R2=0.9973;In the concentration range of 1 ×101?1×104ng/mL,the LPS concentration has a good linear relationship with the current peak value.The linear equation is y=0.26x?44.20,R2=0.9940.The LPS detection limit is 3.5 × 10-3 ng/ml.In summary,Salmonella was used as the object of detection,BIP and RAW264.7 cells were used as identification elements,and the electrochemical workstation was used as the donor,built respectively electrotechnical sensor of bacterial staining based on self-directed PET chip and 3D chemical chip based on paper chip for the detection of Salmonella and LPS in food.