Silver metal induced surface enhanced Raman of bacteria

Bacteria treated with sodium borohydride serve as a nucleating substrate for reduction of silver ions that forms a rough silver metal coating surrounding the microorganism. Corroding away the silver reveals that the general shape and size of the bacteria remain intact. Intense Surface Enhanced Raman spectra of the coated bacteria are measured. The Raman spectra of four different bacteria: Escherichia coli, Acinetobacter calcoaceticus RAG-1, Pseudomonas aeruginosa YS-7, and Bacillus megaterium are all quite similar, suggesting that the spectra are selective and sensitive to a specific molecular species, which dominates the spectra and which is present in all (these) bacteria.