Poly-Si Film Type Nanowire DNA Biosensor with γ-APTES/Nanoparticles Nanocomposite Sensing Membrane

• Main Authors: WANG,SIH-CING, 王思晴
• Other Authors: LIN,JING-JENN
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/41453738589768622659

碩士 === 國立暨南國際大學 === 應用材料及光電工程學系 === 104 === In this thesis, we investigated the DNA sensing performance of poly-Si film type nanowire (FTNW). The width of poly-Si FTNW is only 100 nm but having a large side sensing area. The configuration of the poly-Si FTNW was specifically designed in pattern with an operation current range suitable for DNA detection. The poly-Si surface was coated with γ-APTES and silica nanoparticles nanocomposite growing by solution phase deposition followed with glutaraldehyde modification for grating different types of DNA strains. Synthetic DNA including the single-strained (ss)-homopolymers poly-adenine [poly(A)], poly-thymine [poly-(T)], poly-cytosine [poly(C)], and poly-guanines [poly(G)] were grafted on modified surface as identified by UV/visible spectrometer. The relationships between absorption peak and DNA length, concentration as well as grafting time were analyzed. Good linear relationships between the UV-vis main absorption peak and DNA concentration were observed. It was a reasonable conjecture that the glutaraldehyde molecule on modified surface successfully bonded with all types of synthetic DNA. Characterization of DNA by channel current modulation of FTNW with silica nanoparticles nanocomposite for surface modification showed that, for a fixed number of bases, influence of different types of single-strained DNA on channel current modulation of FTNW was poly (T) > poly (C) > poly (G) > poly (A). The current changes increased linearly with concentration and length of DNA, showing that the effectiveness of the poly-Si FTNW for used as a DNA biosensor. We found that poly-Si FTNW DNA biosensor using the nanoparticles for surface modification could significantly improve the detection range of DNA. The detectable range of poly (A) was improved from 10-10 M ~10-5 M to 10-18 M ~10-5 M, and the lowest detection limit was improved by 8 orders of magnitude; The detectable range of poly (C) was improved from 10-15 M ~ 10-5 M to 10-18 M ~ 10-5 M, and the lowest detection limit was improved by 3 orders of magnitude; The detectable range of poly (G) was improved from 10-15 M ~ 10-5 M to 10-18 M ~ 10-5 M, and the lowest detection limit was improved by 3 orders of magnitude; The detectable range of poly (T) was improved from 10-16 M ~ 10-5 M, and the lowest detection limit was improved by 2 orders of magnitude. Most of the curves showed three linear regions in the detectable range. Reaction-limited and diffusion-limited models were used to qualitatively explain this phenomenon. Compatible with the conventional semiconductor process, the poly-Si FTNW with a large side sensing area, using the γ-APTES+NPs and glutaraldehyde for surface modifications showed good performance as a label-free DNA detection device.