The Appli Cation And Of Biosensors Based On Nanomaterials

In our work the nanomaterials are used to conduct a novel and sensitive biosensor for the determination of DNA sequence.And orther nanoterails such as Y₂O₃ are also studied in the reseach in order to be used in electrochemical biosensors. The details are summarized as follows:(1) A novel and sensitive chemiluminescence (CL) assay for sequence-specific DNA detection based on signal amplification with gold and cobalt nanoparticles (NPs) was reported. The sandwich-type DNA biosensor was fabricated with the amino-functionalized capture DNA immobilized on the magnetic bead and hybridized with one end of target DNA, the other end of which was recognized with a signal DNA probe labeled on the surface of Au NPs. To amplify the detection signals, a single gold NP was modified with 27 cobalt NPs by a reaction between amino-functionalized DNA on the surface of gold NP and carboxyl-functionalized on the surface of cobalt NPs. The hybridization events were monitored by the CL intensity of luminol-H2O2-Co²⁺ after the cobaltous ions were dissolved from the hybrids. This method could detect as low as 6.0×10^-17 M target DNA and the line range was from 1.0×10^-16 to 1.0×10^-15 M.(2) A novel and sensitive chemiluminescenc assay for the sequence specific DNA detection based on the signal amplication with cobalt nanoparticles in larger size was developed on the basis of our preceding work. In this method, wo use cobalt nanoparticles amplified the signal DNA probe without Au nanoparticles. The hybridization events were monitored by the CL intensity of luminol-H₂O₂-Co²⁺ after the cobaltous ions were dissolved from the hybrids. his method could detect as low as 1.6×10^-17 M target DNA and the line range was from 0.6×10⁽-16 to 4.0×10^-16 M. (3) Based on the excellent performance of rare earth elements and nano-materials, We prepared electrode modified with Y₂O₃ nanotubes and we found the Y₂O₃ nanotubes can greatly enhanced conductivity of electrode, so we believe it can be used in the study of electrochemical biosensor in the future.