Fabrication of a Au nanoporous film by self-organization of networked ultrathin nanowires and its application as a surface-enhanced Raman scattering substrate for single-molecule detection.
ABSTRACT Due to its demonstrated usefulness in fields such as trace analysis, biodiagnosis, and in vivo study, surface-enhanced Raman scattering (SERS) has received renewed interest in recent years. Development of SERS substrates is of great importance as the SERS intensity and reproducibility depend strongly on the SERS substrates. In this paper we report the fabrication of Au nanoporous film (NPFs) by self-organization of networked ultrathin Au nanowires for use as SERS substrates. The acquired Au NPFs display controllable thickness, low relative density, and considerable specific surface area. Furthermore, this self-organization of nanowires not only provides abundant junctions between nanowires, 5-20 nm nanopores, and three-dimensional nanowells, but also makes nanopores/nanogaps down to 1-2 nm. These nanoscale characteristics result in a high spatial density of hotspots with Raman enhancement factors up to 10(9). Combined with the uniformity and high purity, our Au NPF provides high-quality substrates for SERS sensing.
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Article: Highly efficient SERS test strips.[show abstract] [hide abstract]
ABSTRACT: We present a facile production approach to highly efficient SERS test strips by physical vapor deposition of silver on paper, which contains natural wrinkle and fibril structures. The SERS test strips open the door to highly sensitive (e.g., 10(-10) M) SERS detection in a convenient fashion.Chemical Communications 05/2012; 48(47):5913-5. · 6.38 Impact Factor
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ABSTRACT: In pH 5.5 2-(N-morpholino)-ethanosulfonic acid buffer solution containing 0.25 M NaCl at 80 °C, the single-stranded substrate DNA hybridizes with the enzyme DNA to form double-stranded DNA (dsDNA). The substrate chain of dsDNA could be cracked catalytically by UO22+ to produce a short single-stranded DNA (ssDNA) that adsorbed on the nanogold (NG) surface to form a stable nanogold–ssDNA conjugate and then further combine with rhodamine 6G (RhG) to form a NG–ssDNA–RhG conjugate that can be monitored by the surface-enhanced resonance Raman scattering (SERRS) spectral technique at 1,360 cm−1. Under the selected conditions, the increased SERRS intensity ΔI 1360 was linear to UO22+ concentration in the range of 5–125 nmol/L, with a detection limit of 1.6 nmol/L. Using a 0.5-μmol/L Hg2+ as enhancer, a 2.5–100-nmol/L UO22+ can be determined.Plasmonics 8(2). · 2.43 Impact Factor