High-sensitivity Electrochemical Biosensor Based On Alumina Nanopore Membrane And Its Application

Biosensors are devices that are sensitive to biological substances and convert their concentration to electrical signals for detection.Biosensors have the function of a receiver and a transducer.They are made of immobilized biosensitive materials such as enzymes,antibodies,antigens and other biologically active substances,suitable physical and chemical converters such as oxygen electrodes,phototube tubes,etc.and Signal amplification device consisting of analysis tools or systems.After years of research,biosensors have been widely used in life sciences,medicine,food industry and environmental testing.The biosensor studied in this paper is a new type of sensor with aptamer and nanotechnology.It has the advantages of low detection limit,high sensitivity,good selectivity and low cost.It attracts more and more attention.Aptamer and nanotechnology have become one of the hot topics in the field of analytical chemistry today due to their advantages of simple and rapid operation,high sensitivity and good specificity.With the continuous improvement and development of aptamer and nanotechnology,it will play a crucial role in biochemistry,disease diagnosis and clinical treatment.In this paper,we use the aptamer and alumina nanoporous membrane combination,the introduction of silicon nanoparticles to achieve the detection of ATP in the blood of rats,and when the complex system contains interfering substances,can still be specifically identified ATP.On this basis,in order to further study the application of this sensor,we have constructed a highly sensitive sensor based on new alumina nanomaterials for the detection of Hg²⁺,Pb²⁺,Sr²⁺.The electrochemical method is simple and easy to operate The limitations of large-scale equipment and instruments,greatly simplifying the experimental steps,is expected to be in clinical medicine,biological analysis and other fields to achieve further applied research.Chapter1.IntroductionIn the first chapter of the article,first introduced the relevant background knowledge of biosensors and the application principle of aptamer and nanometer combined technology.Including:the basic types of biosensors,aptamer technology applications and research in various fields,the introduction of alumina nanopore and future development direction and other knowledge.At last,the working mechanism and its application of aptamer and nanotechnology are introduced emphatically.Chapter2.In this chapter,a novel high-sensitivity sensor based on steric hindrance type,which can be used for rapid ATP detection,is proposed.The scanning electron microscope,fluorescence microscopy imaging technology,differential pulse voltammetry,and electrochemical impedance are used separately.This sensor was characterized.The sensor uses silicon nanoparticle sandwich structure?PAA/H1/H4/H2/SiO₂-NPs?formed by multi-strand DNA chains and alumina nanopore membrane to block ion conduction,and the presence of target ATP can destroy the sandwich structure in the sensor.The smoothness of the ion channel allows the detection of the target ATP to be achieved through its current variation.The application of silicon nanoparticles greatly reduces the volume of space within the PAA pore film,increases the steric hindrance,effectively improves the detection sensitivity and reduces the background signal;in addition,only a very small amount of the sample is applied to the surface of the sensor for incubation during the incubation.And detection also effectively reduces the amount of detection.Experiments show that the linear range of the sensor for ATP detection is 0.025 to0.900 nmol/L,and the detection limits is 13 pM?S/N=3?.When the coexisting substances in the solution exist in large quantities,the detection of ATP by the sensor is still highly specific.Experiments show that the new high-sensitivity sensor based on space block designed by us is easy to operate,low in production cost,and has good regeneration capability.The detection of trace ATP in the blood of mice can be achieved,and it is expected to be applied in the fields of clinical medicine detection,pharmaceutical industry and environmental testing.Chapter3.In this paper,a new type of highly sensitive electrochemical sensor for the detection of Hg²⁺,Pb²⁺,Sr²⁺is mainly based on the technology of establishing aptamer and nanometer.The structure of sensor formed by multi-segment DNA chain modification on alumina nanoporous membrane hinders ion conduction,When Hg²⁺,Pb²⁺and Sr²⁺are present in the system,Hg²⁺can be specifically recognized by using thymine?T?in the nucleic acid sequence to form a special T-Hg-T structure.The G-rich DNA strand can form G-quadruplex with Pb²⁺and Sr²⁺,and the ion channels are smooth.When Hg²⁺,Pb²⁺and Sr²⁺are successively added as mercaptoethanol,DOTA and KP,Nanopore membrane release,making the DNA chain back to a straight chain state,resulting in blocked alumina channel,by detecting the current change to achieve the purpose of detection.The results showed that the linear range of this sensor for detection of Hg²⁺,Pb²⁺and Sr²⁺was 0.05-1.50 nmol/L with detection limits of 0.013,0.017 and 0.0022 nmol/L?S/N=3?.The sensor still shows high specificity for Hg²⁺,Pb²⁺,Sr²⁺when co-existent material with a 100-fold target concentration is present in the sample.This sensor is simple to construct and has good regenerability,which is expected to be applied to the monitoring of drinking water and environmental water.