| Summary: | 碩士 === 國立中正大學 === 化學暨生物化學研究所 === 103 === Biosensor technologies for oligonucleotide sequencing and oligonucleotide assays have become increasingly important. Detection of oligonucleotide samples has been applied to many fields, including medicine and molecular diagnostics for preventative therapy of genetic disorders, prognosis of cancer therapy, and detection of bacteria and virus. According to studies, one of the causes of cancer is related to methylated cytosine. We design an oligonucleotide using part of the sequence which is easily methylated in bladder cancer as the sample.
In this research, we have developed a method that is able to detect oligonucleotide specifically by fiber-optic particle plasmon resonance (FOPPR), which is based on the immobilization of gold nanoparticles on the fiber core surface of an optical fiber. The basis of detection is through the sensitivity of the optical properties of gold nanoparticles to their surrounding environment. We have demonstrated the feasibility by using a free Biotin-modified oligonucleotide as an Amplifier-Probe-DNA and Streptavidin as the signal amplification agent. Because Streptavidin bind to biotin with high affinity ( Kd of 10−14 mol/l ) and specificity. Here the Surface-Probe-DNA was functionalized on the gold nanoparticle surface to detect the Target-DNA. Then we injected the Amplifier-Probe-DNA and Streptavidin to obtain the amplified signals. The Surface-Probe-DNA and Amplifier-Probe-DNA are complementary DNA sequence to different sections of the Target-DNA. Base on this approach, the detection limit is about 10-10 M and the linear dynamic range is 1х10-7 to 1х 10-9 M.
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