Label-Free Fiber-Optic Localized Plsamon Resonance Biosensors for Detection of Oligonucleotides and HLA-B27 mRNA

• Main Authors: Wan-Yun Li, 利宛芸
• Other Authors: Lai-kwan chau
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/97645311749143112526

碩士 === 國立中正大學 === 化學所 === 97 === Using Fiber-Optic Localized Plasmon Resonance (FO-LPR) method, we have developed a novel label-free biosensor for DNA and message RNA (mRNA). Upon functionalization of the colloidal gold surface with an oligonucleotide probe, the hybridization of the probe with complementary DNA or mRNA was interrogated by the unique optical properties of colloidal gold. The thiolated DNA was immobilized onto the gold surface via the well-known self-assembly chemistry, where thiolated DNA is assembled onto a gold surface followed by adsorption of a diluent of an alkanethiol. The diluent not only helps to project the probe DNA off the surface but also resists nonspecific adsorption onto the gold nanoparticle surface. Since the optical properties and hence the attenuated total reflection spectrum of self-assembled gold colloids on the optical fiber changes with the adsorbate induced refractive index of the environment near the colloidal gold surface, the realization of the sensing platform is through the measurement of intensity from the colloidal gold-modified optical fiber. The limit of detection for DNA hybridization was about 10-8~10-11M, depending on the number of base in the target DNA. The FO-LPR method was further applied to detection of mRNA in serum samples from patients. This study, we used real-time PCR to quantify mRNA during HLA-B27 gene expression in patients with Ankylosing Spondylitis and compared with results from FO-LPR method. Results show that mRNA formed during HLA-B27 gene expression can be detected and the sensor response correlate with results from real-time PCR.