Fig. 4

SERS spectral results of bacterial samples using Nano-DEP microfluidic device. a SERS spectra and peak assignment of non-binding (probe signal) type and binding (dual signal) type (the marked peaks are the featured Raman peaks from three Raman tag molecules); (b) SERS spectra and peak assignment of binding type and normal Raman spectra of pure & high-concentration E.coli O157: H7 bacteria (the marked peaks are the Raman signatures from target pathogen, the red color marked ones cannot be clearly identified in the dual-type spectra)