[Zurück]

J Baena, N. Leopold, M. Haberkorn, T. Laurell, J. Nilsson, B. Lendl:
"Airborne Synthesis and Application of a Novel Silver Sol for Sensitive and Reproducible FT-SERS Spectroscopy";
Poster: ICAVS II, Nottingham (UK); 19.08.2003 - 24.08.2003.

In the present communication, a new approach for on-line monitoring of chemical reactions in levitated nL-sized droplets using Raman spectroscopy will be presented on the example of SERS sol synthesis and application for trace analysis. The technique utilizes an automated flow system that feeds a piezoelectric flow-through droplet dispenser for precise reagent supply into a node of an ultrasonic trap. The trap is attached to a FT Raman spectrometer in such a way that the levitated droplet can be monitored continuously. For rapid, on-line SERS sol synthesis a new chemical synthesis route based on the reduction of silver nitrate with hydroxylamine at alkaline pH has been developed. Using the automated flow system solutions of silver nitrate followed by hydroxylamine are dispensed in highly reproducible way into the node of the trap. In doing so SERS sol synthesis can be realized at room temperature and completed within 2 minutes, effectively avoiding any surfaces to which the prepared SERS sol might adsorb.