Electrochemical Microbial Sensor Based On Surface Multi-level 3D Micro-nano Structure

Even in modern society,health and safety problems caused by pathogenic bacteria infection are still an important cause of disease and death,so there is still a huge demand for rapid detection of major pathogenic bacteria.In contrast,the existing methods of pathogen detection have many deficiencies,such as the traditional plate counting method,PCR method and enzyme-linked immunoassay,which are time-consuming,cumbersome and require high operational techniques.Electrochemical biosensor detection of pathogenic bacteria has the characteristics of short time consumption,high sensitivity,simple operation and low detection limit.Compared with other detection methods,it has many advantages.The development of electrochemical biosensors for the detection of pathogenic bacteria is of great significance in food safety and environmental hygiene.According to the above requirements,this paper adopts the technology of nanometer thermal and electroplating technology in flat polymer material surface to construct multi-level three-dimensional micro-nano structure,decorate to specific again capture the typical pathogenic bacteria,staphylococcus aureus antibody,can quickly,efficiently and specificity to detect staphylococcus aureus electrochemical biosensors,It is also used for the detection of Staphylococcus aureus in actual samples.In addition,the effects of the size,morphology and working conditions of the multilevel three-dimensional micro and nano structures on the capture and detection efficiency of Staphylococcus aureus were also studied.The details are as follows:Nano-imprint technology was used to fabricate three-dimensional micro-nano arrays with regular convex squares on the surface of polymer(IPS).Then,the gold nanoclusters were further constructed by electrochemical deposition technology on such arrays to form multilevel three-dimensional micro-nano structures on the surface.After that,sulfur gold bond interaction and amide bond were used to modify anti-Staphylococcus aureus antibody on multi-level three-dimensional micro-nano structure.The efficient and specific interaction of antigen-antibody was used to capture Staphylococcus aureus,and the number of captured Staphylococcus aureus was detected by electrochemical impedance technique.In order to achieve efficient,quantitative detection of Staphylococcus aureus in the sample.In addition,the size of the square array and the distribution density of the gold clusters were optimized.It was found that the length of the sides was the smallest(6μm)and the spacing was the smallest(6μm)among the various surface multistage micro-nano structures.The surface multilevel three-dimensional micro-nano structure with electrochemical deposition time of 75 s had the best capture efficiency for S.aureus.Furthermore,conditions such as the quantity of antibodies on the surface of the sensor and the capture time of bacteria were optimized.Finally,a Staphylococcus aureus electrochemical sensor with a detection limit of 10 CFU/m L and a linear range of10-10~5CFU/m L was obtained.Finally,the application performance of the electrochemical sensor in real samples is verified.In conclusion,the electrochemical microbial microsensor prepared in this paper can specifically detect Staphylococcus aureus,a typical pathogenic bacterium,and has the advantages of high sensitivity,simple operation,rapid,etc.,which is expected to be applied to the monitoring of food safety and environmental health.