Ordered Ag/Si nanowires array: wide-range surface-enhanced Raman spectroscopy for reproducible biomolecule detection
| Autor: | Tailun Wong, Yingqi Zhao, Lifang He, Shuit-Tong Lee, Xuejin Zhang, Jian-An Huang, Ying-San Chui, Wenjun Zhang |
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| Rok vydání: | 2013 |
| Předmět: |
chemistry.chemical_classification
Reproducibility Silicon Materials science Silver Nanowires Mechanical Engineering Biomolecule Surface plasmon Nanowire Reproducibility of Results Bioengineering Nanotechnology General Chemistry Surface-enhanced Raman spectroscopy Condensed Matter Physics Spectrum Analysis Raman symbols.namesake chemistry Electric field symbols Microscopy Electron Scanning General Materials Science Excitation Raman scattering |
| Zdroj: | Nano letters. 13(11) |
| ISSN: | 1530-6992 |
| Popis: | Surface-enhanced Raman scattering (SERS) systems utilizing the interparticle nanogaps as hot spots have demonstrated ultrasensitive single-molecule detection with excellent selectivity yet the electric fields are too confined in the small nanogaps to enable reproducible biomolecule detections. Here, guided by finite-difference-time-domain simulation, we report hexagonal-packed silver-coated silicon nanowire (Ag/SiNW) arrays as a nanogap-free SERS system with wide-range electric fields and controlled interwire separation. Significantly, the system achieves a SERS detection of long double-strand DNA of 25-50 nm in length with a relative standard deviation (RSD) of 14% for measurements of above 4000 spots over an area of 200 × 200 μm(2). The high reproducibility in the SERS detection is attributed to (1) the large interwire spacing of 150 nm that allows access and excitation of large biomolecules; and (2) 600 nm wide-range electric field generated by propagating surface plasmons along the surface of continuous Ag coating on a SiNW. Moreover, a reproducible multiplex SERS measurement is also demonstrated with RSDs of 7-16% with an enhancement factor of ~10(6). The above results show that the ordered Ag/SiNW array system may serve as an excellent SERS platform for practical chemical and biological detection. |
| Databáze: | OpenAIRE |
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