Comparison of fibre-optic SERS sensors with differently prepared tips

Fibre-optic sensors using surface-enhanced Raman scattering (SERS) with a s ingle fibre for both the excitation and the signal collection require the p reparation of properly roughened metal films at the tip of the fibres. Suit able techniques are slow evaporation of metals forming island-films, vacuum deposition of metal films on alumina or diamond particles, and evaporation of metals on sandblast-roughened fibre tips. All of these preparations res ult in SERS-active sensor tips with similar enhancements of the Raman signa l intensities. The newly proposed sandblast method may be superior in pract ical applications because it promises the highest durability and the easies t regeneration of the thus produced sensors. (C) 1998 Elsevier Science S.A. All rights reserved.