Separation and detection of multiple pathogens in a food matrix by magnetic SERS nanoprobes

Wang, Yuling, Ravindranath, Sandeep and Irudayaraj, Joseph (2011) Separation and detection of multiple pathogens in a food matrix by magnetic SERS nanoprobes. Analytical and Bioanalytical Chemistry, 399 3: 1271-1278. doi:10.1007/s00216-010-4453-6

Author Wang, Yuling
Ravindranath, Sandeep
Irudayaraj, Joseph
Title Separation and detection of multiple pathogens in a food matrix by magnetic SERS nanoprobes
Journal name Analytical and Bioanalytical Chemistry   Check publisher's open access policy
ISSN 1618-2642
Publication date 2011
Sub-type Article (original research)
DOI 10.1007/s00216-010-4453-6
Open Access Status
Volume 399
Issue 3
Start page 1271
End page 1278
Total pages 8
Place of publication Heidelberg, Germany
Publisher Springer
Language eng
Abstract A rapid and sensitive method was developed here for separation and detection of multiple pathogens in food matrix by magnetic surface-enhanced Raman scattering (SERS) nanoprobes. Silica-coated magnetic probes (MNPs@SiO 2) of ∼100 nm in diameter were first prepared via the reverse microemulsion method using cetyltrimethylammonium bromide as a surfactant and tetraethyl orthosilicate as the silica precursor. The as-prepared MNPs@SiO 2 were functionalized with specific pathogen antibodies to first capture threat agents directly from a food matrix followed by detection using an optical approach enabled by SERS. In this scheme, pathogens were first immuno-magnetically captured with MNPs@SiO2, and pathogen-specific SERS probes (gold nanoparticles integrated with a Raman reporter) were functionalized with corresponding antibodies to allow the formation of a sandwich assay to complete the sensor module for the detection of multiple pathogens in selected food matrices, just changing the kinds of Raman reporters on SERS probes. Here, up to two key pathogens, Salmonella enterica serovar Typhimurium and Staphylococcus aureus, were selected as a model to illustrate the probability of this scheme for multiple pathogens detection. The lowest cell concentration detected in spinach solution was 103 CFU/mL. A blind test conducted in peanut butter validated the limit of detection as 10 3 CFU/mL with high specificity, demonstrating the potential of this approach in complex matrices. [Figure not available: see fulltext.]
Keyword Food matrix
Multiplex pathogen detection
Silica-coated magnetic nanoparticles
Surface-enhanced Raman scattering
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: Australian Institute for Bioengineering and Nanotechnology Publications
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