Silver-particle-based surface-enhanced resonance Raman scattering spectroscopy for biomolecular sensing and recognition.
We demonstrate in this work that 2-microm-sized Ag (microAg) powders can be used as a core material for constructing biomolecular sensing/recognition units operating via surface-enhanced resonance Raman scattering (SERRS). This is possible because microAg powders are very efficient substrates for both the diffuse reflectance IR and the surface-enhanced Raman scattering-SERRS spectroscopic characterization of molecular adsorbates prepared in a similar manner on silver surfaces. Besides, the agglomeration of microAg particles in a buffer solution can be prevented by the layer-by-layer deposition of cationic and anionic polyelectrolytes such as poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA). In this particular study, we used rhodamine B isothiocyanate (RhBITC) as a SERRS marker molecule, and microAg powders adsorbed consecutively with RhBITC and PAH-PAA bilayers were finally derivatized with biotinylated poly(L-lysine). On the basis of the nature of the SERRS peaks of RhBITC, those microAg powders were confirmed to selectively recognize streptavidin molecules down to concentrations of 10(-10) g mL-1. Since a number of different molecules can be used as SERS-SERRS marker molecules, the present method proves to be an invaluable tool for multiplex biomolecular sensing/recognition via SERS and SERRS.
Kim
Kwan
K
Laboratory of Intelligent Interfaces, Department of Chemistry, Seoul National University, Seoul, 151-742, South Korea. kwankim@snu.ac.kr
Lee
Hyun Sook
HS
Kim
Nam Hoon
NH
D000180:Acrylic Resins / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D010316:Particle Size; D011073:Polyamines / Q000737:chemistry; D011208:Powders; D011506:Proteins / Q000032:analysis*; D012235:Rhodamines / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000295:instrumentation / Q000379:methods*; D019809:Streptavidin / Q000032:analysis
D000180:Acrylic Resins; D005456:Fluorescent Dyes; D011073:Polyamines; D011208:Powders; D011506:Proteins; D012235:Rhodamines; C063994:polyallylamine; D012834:Silver; C006903:carbopol 940; D019809:Streptavidin; C027755:rhodamine isothiocyanate