Construction Of Electrochemical Biosensors Based On Functionalized Nanomaterials And Their Application In Bioassay

Biosensors is an subject involved biology, chemistry, electronic science, owing to advantages such as simple operation, fast response, high sensitivity, good selectivity and so on. They have broad application in medical, environmental, food and many other fields. In recent years, with the innovation of new technology, the optimization and upgrading of electronic equipment, the development of new materials dominated by nanomaterials, has enhance the development of biological sensors into a high-speed level. However, there is also a great need to construct an accurate, quick, efficient and portable biosensor.(1) A novel sensor interface based on Au nanoparticles dotted carbon nanotubes-graphene composites modified electrode was constructed, which has excellent electric conductivity and large specific surface area, and benefical for biomolecules’s immobilization. At the same time, using functionalized SiO2microspheres as cariier to amplify signals, a facile and sensitive electrochemical immunosensor for detection of human chorionic gonadotrophin was proposed.(2) Combined with microfluidic chip technology, a folding paper based Au nanoparticles/graphene modified screen printed electrodes was constructed. Using dsDNA as signal carrier, together with complementary ssDNA modified on nanoporous gold. Making full use of nanoporous gold:big specific surface surface area and biological compatibility, a simple, sensitive, cheap and stable DNA sensor was developed. And the results were acceptable.(3) A simple approach based on exfoliating and disintegrating treatments for graphite oxide, followed by hydrothermal synthesis was developed to prepare water-soluble graphene quantum dots, and the optical properties were also studied. More important, a newly ECL was observed from GQDs with H2O2as coreactant, and the ECL mechanism is investigated in detail. Owing to the low toxicity and well ECL properties of GQDs, employing SiO2nanospheres as signal carrier, a novel SiO2/GQDs ECL signal amplification labels were synthesized based on which a ultrasensitive ECL aptammer sensor was proposed.