2013 Annual Report
2. Detect and characterize foodborne pathogens, toxins, and bacterial threat agents with rapid optical methods.
3. Develop and evaluate detection methods for foodborne pathogens and toxins with nanotechnology.
Relationship of Eggshell Microstructure to Chemical Composition. Low eggshell strength leads to development of cracks, allowing contamination of eggs by pathogenic bacteria and loss to the industry. A Laser Induced Breakdown Spectroscopy (LIBS) method was developed to correlate the chemical composition of the eggshell with microstructural features that enhance the propensity of eggshells to become damaged. Eggshell hardness was related to the ratio of calcium components detected by the LIBS system.
Classification of Salmonella serotypes with Laser Induced Breakdown Spectroscopy (LIBS). A LIBS method was developed to identify five Salmonella serotypes based on the atomic spectral signatures emitted from the laser induced plasma. Colony films of the different serotypes were created on stainless steel and the LIBS spectra of the resulting films were subsequently treated via a hierarchical clustering method which successfully identified each serotype.
Classification of Foodborne Pathogens with Hyperspectral Microscope Imaging (HMI). A HMI method was developed to classify foodborne pathogens from the optical properties of bacterial cells in micro colony samples using their spectral signatures. The HMI method was able to differentiate five serotypes of Salmonella and Staphylococcus with a support vector machine classification algorithm. The results can be used for a rapid presumptive screening method for foodborne pathogens.
Salmonella Typhimurium (ST) Identification with DNA aptamers using Surface Enhanced Raman Scattering (SERS). A special substrate was fabricated and tested with SERS to produce a label-free, specific detection of ST from poultry carcass rinses. The substrate uses a silver nanorod array that have special binding reagents, known as aptamers, to capture the ST cells which are then detected by the SERS system. Further optimization for binding conditions and fabrication of device is needed for improving the lower limit of detection.
Nanobiosensor for Ricin Detection with Atomic Force Microscopy (AFM) and Surface Plasmon Resonance (SPR). Nucleic acid aptamers was used as binding reagents for the label-free detection of biomolecules. The specific interactions between ricin and its corresponding aptamer were measured with AFM and SPR spectrometry. The specific binding site on the aptamer molecule was clearly recognized by the AFM recognition images. Aptamers can be integrated into various detection platforms and provide versatile applications for fast detection and analysis related to biosafety and biosecurity.
Yoon, S.C., Windham, W.R., Ladely, S.R., Heitschmidt, G.W., Lawrence, K.C., Park, B., Narang, N., Cray Jr, W.C. 2013. Hyperspectral imaging for differentiating colonies of non-O157 shiga-toxin producing echerichia coli (STEC) serogroups on spread plates of pure cultures. Journal of Near Infrared Spectroscopy. 21(2):81-95.
Yoon, S.C., Windham, W.R., Ladely, S.R., Heitschmidt, G.W., Lawrence, K.C., Park, B., Narang, N., Cray Jr, W.C. 2013. Differentiation of big-six non-O157 shiga-toxin producing escherichia coli (STEC) on spread plates of mixed cultures using hyperspectral imaging. Journal of Food Measurement & Characterization. 7(2):47-59.
Park, B., Yoon, S.C., Lee, S., Sundaram, J., Windham, W.R., Hinton Jr, A., Lawrence, K.C. 2012. Acousto-optic tunable filter hyperspectral microscope imaging for identifying foodborne pathogens. Transactions of the ASABE. 55(5):1997-2006.
Sundaram, J., Park, B., Hinton Jr, A., Lawrence, K.C., Kwon, Y. 2013. Detection and differentiation of salmonella serotypes using surface enhanced Raman scattering (SERS) technique. Journal of Food Measurement & Characterization. 7(1):1-12.
Sundaram, J., Park, B., Yongkuk, K. 2013. Stable silver/biopolymer hybrid plasmonic nanostructures for high performance surface enhanced raman scattering (SERS). Journal of Nanoscience and Nanotechnology. 13(8):5382-5390.
Sundaram, J., Park, B., Kwon, Y., Lawrence, K.C. 2013. Surface enhaced raman scattering (SERS) with biopolymer encapsulated silver nanosubstrates for rapid detection of foodborne pathogens. International Journal of Food Microbiology. DOI:10.1016/j.ijfoodmicro.2013.05.013.
Windham, W.R., Yoon, S.C., Ladely, S.R., Haley, J.A., Lawrence, K.C., Park, B., Narang, N., Cray Jr, W.C. 2013. Hyperspectral imaging of shiga toxin-producing escherichia coli serogroups O26, O45, O103, O111, O121, and O145 on Rainbow Agar. Journal of Food Protection. 76(7):1129-1136.