<title>Surface-enhanced Raman scattering spectra of TvNPV polyhedrin protein in Ag sol</title>

Abstract

The surface-enhanced Raman Scattering (SERS) spectra of insect virus: the Polyhedrin Protein and Trabala Vishnou Nuclear Polyhedrosis Virus (TvNPV-PP) adsorbed on the surface of silver colloid particles and their Ordinary Raman Scattering (ORS) spectrum were investigated. The SERS spectra and the ORS spectrum of TvNPV-PP show their correlation. In ORS spectrum of TvNPV-PP. The intense amide I at 1656 nm<SUP>-1</SUP>, the medium-intense amide I 1673 cm<SUP>-1</SUP> and a week amide III at 1280 cm<SUP>-1</SUP> show that TvNPV-PP has predominantly (alpha) -helical and (beta) - sheet structure. In SERS spectra of TvNPV-PP the intense bands related to carboxylate groups vibrations suggest that TvNPV-PP are adsorbed on the silver colloid surface through the carboxylate groups. The bands of amide I and amide III could not be observed in SERS residues increased their distance from Ag surface and weaken the enhanced effect of the corresponding vibrations. Chemisorption is a main mechanism in the SERS spectra on silver hydrosols for TvNPV- PP and its mechanism of enhancement has a short-range character. The SERS enhancement factor is approximately 10<SUP>2</SUP>.