Upconversion Nanoprobes Based on a Horseradish Peroxidase-Regulated Dual-Mode Strategy for the Ultrasensitive Detection of Staphylococcus aureus in Meat.
Qin OuyangLi WangWaqas AhmadYongcun YangQuansheng ChenPublished in: Journal of agricultural and food chemistry (2021)
Staphylococcus aureus (S. aureus) is one of the foodborne pathogens that can cause infectious diseases and food poisoning. Herein, colorimetric and fluorescent dual-mode nanoprobes were developed for ultrasensitive detection of S. aureus to immediately respond to public health emergencies, reduce false positives, and improve measurement accuracy and persuasiveness. The nanoprobe consists of aptamer-labeled magnetic nanoparticles (apt-MNPs) as the capture signal probe and horseradish peroxidase and complementary DNA-functionalized upconversion nanoparticles (HRP-UCNPs-cDNA) as the chromogenic signal probe. In the absence of S. aureus, the probe forms an immune complex through base complementation with an observable signal. When S. aureus is introduced to this system, it preferentially binds to the apt-MNPs, releasing HRP-UCNPs-cDNA from the apt-MNPs and restoring the chromogenic probe signal. Under optimum conditions, an ultrasensitive assay of S. aureus was obtained, with limits of detection of 22 CFU mL-1 for fluorescence and 20 CFU mL-1 for colorimetry in a linear range of 56-5.6 × 106 CFU mL-1. Additionally, the standard plate counting method confirmed the reliability and accuracy of the established nanoprobe with an insignificant difference. Hence, the developed dual-mode platform has extensive application prospects for speedy and specific determination of S. aureus in meat.
Keyphrases
- quantum dots
- living cells
- label free
- sensitive detection
- staphylococcus aureus
- energy transfer
- single molecule
- gold nanoparticles
- fluorescent probe
- loop mediated isothermal amplification
- public health
- magnetic nanoparticles
- infectious diseases
- molecularly imprinted
- hydrogen peroxide
- high throughput
- real time pcr
- biofilm formation
- transcription factor
- computed tomography
- climate change
- nitric oxide
- methicillin resistant staphylococcus aureus
- solid phase extraction
- multidrug resistant
- current status
- circulating tumor
- escherichia coli