Fabrication Of Electrochemical DNA Biosensors Based On Nanomaterials

DNA electrochemical biosensor is a DNA biosensor which based on electrochemistry; it is a simple and sensitive technology which used detected DNA hybridization. It becomes increasing important in clinical gene diagnosis, epidemic prevention, and environmental protection. In this work, we using the unique properties of nanomaterials with the electrochemistry, nucleic acid hybridization, and successfully fabricated various novels, sensitive, exact DNA electrochemical biosensor. The dissertation includes four chapters:Chapter I: Introduced the DNA electrochemical biosensor, research progress, and nanomaterials application in DNA electrochemical biosensor.Chapter II: We fabricated a modified electrode based on MWCNTs, ploymole, and gold nanoparticles, and then probe DNA was immobilized on the surface of gold nanoparticle through a 5?-thiol-linker. DPV was used to detect hybridization events using adriamycin as an electroactive indicator. The DNA biosensor exhibited excellent sensitivity, selectivity, stability and reproducibility.Chapter III: The Ploy-L-lysine (PLL) film was electropolymerized onto the surface of electrode, and the modified electrode was subsequently immersed in gold nanoparticles (AuNPs) solution to prepared AuNPs/PLL/GCE. We fabricated a novel and high sensitivity DNA biosensor based on chronocoulometric, and used DPV to optimize the experiment conditions.ChapterⅣ: Firstly we fabricated ZnOnanowires/MWCNTs modified electrode, then the gold nanoparticles were electrochemical deposition on the modified electrode, the probe DNA was assembly on the electrode by Au-S. The process was monitored by DPV and SEM, the capability of the sensor was studied by the reduction peak current of RuHex. The result shows that the DNA biosensor exhibit high sensitivity and have largo linear range.