Research of Label-free Grating Coupling Biosensor Modified with Gold Nanoparticles

• Main Authors: KAO, TSUNG-HUA, 高從華
• Other Authors: HSIEH, WEN-HSIN
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/b3r2y5

碩士 === 國立中正大學 === 機械工程系研究所 === 105 === In this study, we immobilize the gold nanoparticles (AuNPs) on a label-free biosensor which uses grating waveguide couplers for sensitivity detection and immunoassay of dinitrophenyl/anti-dinitrophenyl antibody (DNP/anti-DNP). In terms of fabrication processes, the injection molding and sputtering are used, by adjusting the sputtering oxygen content and sputtering time to optimize the chip sensitivity. When the sputtering oxygen content is 40% and the thickness of the waveguide layer is 90 nm, the biosensor has the optimum sensitivity of -35 RIU^-1, when the refractive index of sucrose solution changes from 1.3355 to 1.343. This study develops a dual-channel grating coupled biosensor to investigate the effect of immobilized location (the grating or the waveguide) of AuNPs on the sensitivity. The sensitivity of the biosensor’s grating is -18.14 ±0.87 RIU^-1 (n=3), and the sensitivity after modified AuNPs is -11.93 ±0.16 RIU^-1 (n=3). After AuNPs are modified on the waveguide, the sensitivity of the biosensor improves from -0.12 ± 0.38 RIU^-1 (n=3) to -1.47 ± 0.22 RIU^-1 (n=3). Finally, this study tests the immunoassay of DNP/anti-DNP. The measured average limit of detection (LOD) of the unmodified biosensor is 1.11×10^-7 ±2.67×10^-8 g/ml (n=3), and the best LOD is 8.08×10^-8 through DNP/anti-DNP interaction；and the measured average LOD of the AuNPs modified biosensor is 6.05×10^-8±4.61×10^-9 g/ml (n=3) , and the best LOD is 5.54×10^-8 g/ml through DNP/anti-DNP interaction. This indicates that the AuNPs improves the performance of the biosensor in the immunoassay of DNP/anti-DNP.