| DNA electrochemical biosensor is a simple and sensitive technologyfor the DNA hybridization detection. It has become increasing importantin clinical gene diagnosis, epidemic prevention, and environmentalmonitoring. In this work, we used the unique properties of nano-materials withmodern electrochemical technology, nucleic acid hybridization, andsuccessfully fabricated several sensitive, novel and exact DNA electrochemicalbiosensors. The dissertation includes four chapters:Chapter Ⅰ: A review is given on the introduction of electrochemicalDNA biosensor, research progress, and nano-materials application inDNA biosensor.Chapter Ⅱ: Ferulic acid (FA) was firstly electropolymerizated on thesurface of the electrode modified with MWCNTs, and AuNPs weresubsequently introduced to the surface of the PFA film byelectrochemical deposition. Finally, DNA probes (HS-DNA) wereimmobilized on the surface of the AuNPs/PFA/MWCNTs/GCE via Au-Sbond. Hexaammineruthenium(Ⅲ) chloride (RuHex) was used as theelectrochemical indicator. We fabricated a novel and high sensitivityDNA biosensor based on chronocoulometric.Chapter Ⅲ: We developed a hybrid biosensor composed of reducedgraphene oxide (rGO) sheets decorated with gold nanoparticles (Au NPs)for sequence-specific DNA detection. DPV was utilized to monitor the DNA hybridization event by measuring the changes in peak current of theintercalated adriamycin. The DNA biosensor exhibited excellentsensitivity, selectivity, stability and reproducibility.Chapter Ⅳ: In the assay, we employed a hairpin DNA probe duallylabeled with mercapto and biotin at the5′and3′end, respectively. Theprobe DNA was assembly on the gold electrode by Au-S. Host-guesttechnique and gold nanoparticles (Au NPs) with reporter DNA (rDNA)could significant amplify the impedance signal. The hybridizationdetection was monitored by electrochemical impedance spectroscopy(EIS), and the result showed that the DNA biosensor exhibited highsensitivity and had large linear range. |
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