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Updated: May 7, 2026
Surface Enhanced Raman Spectroscopy Detection of Biomolecules Using EBL Fabricated Nanostructured Substrates
Published on: March 20, 2015
Ordered Ag/Si nanowires array: wide-range surface-enhanced Raman spectroscopy for reproducible biomolecule detection
Jian-An Huang1, Ying-Qi Zhao, Xue-Jin Zhang
1Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Materials Science, City University of Hong Kong , Hong Kong SAR, China.
This study introduces a novel nanogap-free Surface-Enhanced Raman Scattering (SERS) platform using silver-coated silicon nanowire arrays for reproducible biomolecule detection. The system demonstrates high sensitivity and selectivity for DNA, paving the way for advanced chemical and biological sensing applications.
Area of Science:
- Nanotechnology
- Plasmonics
- Spectroscopy
Background:
- Traditional Surface-Enhanced Raman Scattering (SERS) systems rely on nanogaps, which confine electric fields, limiting reproducible detection of large biomolecules.
- Ultrasensitive single-molecule detection is achievable with SERS, but reproducibility remains a challenge due to electric field confinement in small nanogaps.
Purpose of the Study:
- To develop a nanogap-free SERS system using hexagonal-packed silver-coated silicon nanowire (Ag/SiNW) arrays.
- To achieve reproducible detection of large biomolecules, specifically long double-strand DNA.
- To investigate the impact of controlled interwire separation and wide-range electric fields on SERS performance.
Main Methods:
- Finite-difference-time-domain (FDTD) simulation guided the design of the Ag/SiNW array.
- Fabrication of hexagonal-packed Ag/SiNW arrays with controlled interwire separation (150 nm).
- SERS measurements of long double-strand DNA and multiplexed analytes.
Main Results:
- The Ag/SiNW array achieved reproducible SERS detection of 25-50 nm long DNA with a relative standard deviation (RSD) of 14% over a large area.
- Reproducibility is attributed to wide interwire spacing (150 nm) and a 600 nm wide-range electric field generated by surface plasmons.
- Multiplex SERS measurements showed RSDs of 7-16% with an enhancement factor of approximately 10^6.
Conclusions:
- The developed nanogap-free Ag/SiNW array platform overcomes the limitations of confined electric fields in traditional SERS systems.
- The system offers a promising solution for reproducible and ultrasensitive detection of large biomolecules.
- The ordered Ag/SiNW array serves as an excellent platform for practical chemical and biological detection applications.
