Figure 2. SERS on overnight cultures of PAO1, the DK02 lineage and their lasR mutated strains.

(a) SERS on emissions from overnight cultures of P. aeruginosa PAO1, wild type vs. its engineered lasR mutated strain PA-SD2. (b) SERS on emissions from overnight cultures of the P. aeruginosa DK02 lineage, wild type from 1973 vs. the lasR mutated strain from 1979. Both wild types show intense CN signals at 2135 cm⁻¹ and also a small peak at 2189 cm⁻¹ due to formation of the [Au(CN)₂]⁻ complex, whereas the lasR mutated strains emit no HCN. Spectra of LB emissions are included as reference.