Summary: | 碩士 === 國立臺灣大學 === 化學研究所 === 100 === Silicon nanowire field-effect transistors (SiNW-FETs) have drawn great attention because of their potential as a label-free, real-time, and ultra-sensitive sensor for biomolecular detections. As a biological sensor, the surface of a SiNW-FET device was conventionally all area modified (AAM) with receptors, covering not only the minute SiNW surface area but also the relatively massive surrounding substrate area. However, target molecules could be captured on the upstream substrate area before
reaching the SiNW surface in sensing measurements, thus jeopardizing the detection sensitivity. In this study, we have successfully fabricated SiNW-FETs with the
selective surface modification (SSM) of receptors only on the SiNW sensing surface via gas-phase premodification and a bottom-up fabrication technique. Our results
show that a SSM SiNW-FET, exhibiting desirable electrical characteristics with regard to ohmic contact and high transconductance, has the merits of faster response time, less sample requirements, and much improved detection sensitivity. Besides, we integrated SiNW-FET with a lipid bilayer to mimic the cell membrane for biological
research, especially for the membrane protein studies. Our results show that a 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) lipid bilayer membrane with
single or double lipid bilayers could be homogeneously formed on the SiNW-FET surface via a vesicle fusion method. However, because the shielding of the lipid
bilayers on the underlying SiNW, signals were reduced in electrical measurement. To improve the signal acquisition from a lipid bilayer membrane covered SiNW-FET, we
demonstrated that the electrical signals and the detection limit can be enhanced by utilizing a multiple-parallel-connection (MPC) SiNW-FET system.
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