Abstract
A non-labeled, portable plasmonic biosensor-based device was developed to enable the ultra-sensitive and selective detection of Salmonella typhimurium in pork meat samples. Specifically, a plasmonic sensor, using the self-assembly of gold nanoparticles (AuNPs) to achieve a regulated diameter of 20 nm for the AuNP monolayers, was used to conduct high-density deposition on a transparent substrate, which produced longitudinal wavelength extinction shifts via a localized surface plasmon resonance (LSPR) signal. The developed aptamers conjugated to the LSPR sensing chips revealed an ultra-sensitive upper limit of detection (LOD) of approximately 104 cfu/mL for S. typhimurium in pure culture under the optimal assay conditions, with a total analysis time of 30–35 min. When the LSPR sensing chips were applied on artificially contaminated pork meat samples, S. typhimurium in the spiked pork meat samples was also detected at an LOD of 1.0 × 104 cfu/mL. The developed method could detect S. typhimurium in spiked pork meat samples without a pre-enrichment step. Additionally, the LSPR sensing chips developed against S. typhimurium were not susceptible to any effect of the food matrix or background contaminant microflora. These findings confirmed that the developed gold nanoparticle-aptamer-based LSPR sensing chips could facilitate sensitive detection of S. typhimurium in food samples.
Highlights
The risk posed to human health by foodborne diseases has increased over the last few years[1, 2], and these diseases cause many human health problems worldwide[3, 4]
We successfully developed an aptamer-based localized surface plasmon resonance (LSPR) sensing strategy for the detection of foodborne pathogenic bacterial strain S. typhimurium
The AuNPs were synthesized with a controlled size (using various approaches, such as reduced precursors, and varying the Au (III) ion to stabilize it) that was useful for sensitive detection, according to a previously reported method[28]
Summary
The risk posed to human health by foodborne diseases has increased over the last few years[1, 2], and these diseases cause many human health problems worldwide[3, 4]. Several modern alternative techniques have been established to detect or diagnose S. typhimurium, such as electrochemical sensors, surface plasmon resonance sensors, fiber-optic biosensors, chemiluminescence, microfluidic devices, impedimetric immunosensors, and conductometric methods[15,16,17] These techniques require well-trained technicians and the identification of the pathogens in large concentrations. Various types of LSPR sensors have been established and used for the detection of environmentally toxic heavy ions, protein toxins, carbohydrates, caseins, nucleic acids, and biomolecules (biotin-streptavidin), as well as in immune assays[24,25,26,27] Many of these LSPR biosensors have low reproducibility, and it is difficult to immobilize large areas of plasmonic-active nanoparticles while reducing the detection limit. LSPR sensing chips, which are straightforward, economical, and capable of the rapid identification of S. typhimurium, were developed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
