Construction Of Homogeneous Electrochemical Biosensors Based On Nanomaterials And Detection Applications Of Disease-related Proteins

Disease-related proteins as biomarkers,have great value in the early diagnosis and treatment of diseases.Choosing appropriate detection means to achieve semi-quantitative/ quantitative detection of biomarkers is the key to clinical research.The emergence of biosensors provides a fast,sensitive and efficient new means for targets detection.Using nucleic acid aptamer as recognition tool,a homogeneous biosensor is constructed.The electrochemical and UV-vis methods are used to achieve rapid and sensitive detection of target substances,which provides new ideas and methods for early diagnosis and treatment of diseases.The main research contents of this paper based on the construction of homogeneous biosensors for disease-related proteins detection are as follows:1.A label-free homogeneous electrochemical aptasensor based on sandwich-type structure for thrombin detectionThe two thrombin binding aptamers are separately modified on the surface of magnetic beads and HAP nanoparticles to serve as separation probe and signal probe.When the target is present in the solution,aptamers specifically recognize thrombin and a sandwich-type structure is formed in the solution.With the aid of magnetic separation,the signal probe is introduced into the detection system to achieve homogeneous biosensing.The homogeneous reaction,occurred on the surface of electrode,reduces steric hindrance,improves sensitivity and precision of the experiment and achieves sensitive detection of the target.In addition,the sensor also has good selection performance to specifically identify the target substance.2.DNA synergistic enzymatic cascade reaction for electrochemical bioassayA homogeneous electrochemical biosensor for detecting thrombin is constructed based on enzyme-mediated cascade reaction and dual signal amplification strategy.Wherein,the DNA probe is not only used as recognition probe to specifically bind the target substance thrombin but also acts as a signal source to synergize with the products of the enzyme-mediated cascade reaction to react with the substrate forming an electroactive substance.Besides,in this biosensing platform,the dual signal amplification strategy achieves sensitive detection of the target substance,and the detection limit is 0.26 fM,realizing rapid and sensitive detection of thrombin.3.A dual-channel homogeneous aptasensor combined colorimetric and electrochemical strategy for thrombin detectionA two-channel homogeneous biosensing platform is constructed based on colorimetric and electrochemical analysis methods for bioassay.Thrombin is selected as a template molecule,and two kinds of signal substances are separated by magnetic separation technology realizing the UV-vis and electrochemical detection of thrombin simultaneously.Moreover,the two methods confirm each other,improve the accuracy and diversity of detection.What's more,It has provided a new method/prospect for the simultaneous detection upon the target molecule based on the comnbination of optical and electrical behavior...