Submitted to: Spectroscopy Magazine
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/16/2008
Publication Date: 2/1/2008
Citation: Liu, Y., Chen, Y., Nou, X., Kim, M.S., Chao, K. 2008. Label-free sers for rapid and simultaneous species identification of escherichia coli, listeria monocytogenes, and salmonella typhimonium bacteria. Spectroscopy Magazine. 12(2):48-54. Interpretive Summary: Recently, we have developed silver colloidal nanoparticle based surface-enhanced Raman scattering (SERS) spectroscopy as a potential tool for the rapid and routine detection of E. coli and L. monocytogenes. Compared to conventional, PCR, and biosensors, the established procedure has one outstanding merit, that is, incubated bacterial cultures were directly mixed with silver colloids and required no antibodies and other pretreatment. Such a simple and easy sampling not only limits the procedural steps and the use of chemical reagents, but also reduces the likelihood of bacterial cross-contamination. This study presents the further results of our examination on different bacterial species for the characteristic bands and subsequent identification. The obtained result provides agricultural /medical engineers and food safety researchers a new sight in applying both nanotechnology and Raman spectroscopy for rapid, specific, and routine screening of the presence of bacteria in processing of raw materials and ready-to-eat food products, in manufacturing process control, and in monitoring of cleaning and hygiene practices.
Technical Abstract: The need for rapid detection of foodborne bacteria has long been a hot topic from policy makers to manufacturers. Traditional method, nucleic acid based on PCR, and antibody based biosensors have been developed as viable tools to identify the bacteria. Generally, these methods are labor-intensive and multi-step procedure, and also require species-specific antibodies / probe reagents. Colloidal silver SERS, as demonstrated here, could be an important alternative technique in the rapid and simultaneous screening of the presence of three most outbreak bacteria due to the exclusive biomarkers, label-free and easy sampling attribute.