Ordered Ag/Si nanowires array : Wide-range surface-enhanced raman spectroscopy for reproducible biomolecule detection

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

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Author(s)

  • Jian-An Huang
  • Ying-Qi Zhao
  • Xue-Jin Zhang
  • Li-Fang He
  • Tai-Lun Wong
  • Ying-San Chui
  • Shuit-Tong Lee

Detail(s)

Original languageEnglish
Pages (from-to)5039-5045
Journal / PublicationNano Letters
Volume13
Issue number11
Online published4 Oct 2013
Publication statusPublished - 13 Nov 2013

Abstract

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 μm2. 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. © 2013 American Chemical Society.

Research Area(s)

  • biomolecule detections, multiplex detections, nanowires array, reproducibility, Wide-range SERS

Citation Format(s)

Ordered Ag/Si nanowires array : Wide-range surface-enhanced raman spectroscopy for reproducible biomolecule detection. / Huang, Jian-An; Zhao, Ying-Qi; Zhang, Xue-Jin; He, Li-Fang; Wong, Tai-Lun; Chui, Ying-San; Zhang, Wen-Jun; Lee, Shuit-Tong.

In: Nano Letters, Vol. 13, No. 11, 13.11.2013, p. 5039-5045.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal