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Updated: Jul 30, 2026
Rapid Homogeneous Detection of Biological Assays Using Magnetic Modulation Biosensing System
Published on: June 13, 2010
Detection of Vibrio parahaemolyticus Based on Magnetic and Upconversion Nanoparticles Combined with Aptamers
Xinjie Song1, Wei Li2, Li Wu1
1Zhejiang Provincial Key Laboratory of Chemical and Biological Processing Technology for Agricultural Products, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Liuxia Street Number 318, Hangzhou 310023, China.
Abstract:
Vibrio parahaemolyticus is a halophilic and heat-labile gram-negative bacterium and is the most prevalent foodborne bacterium in seafood. In order to develop a rapid and sensitive method for detecting the foodborne pathogenic bacterium Vibrio parahaemolyticus, an aptamer-modified magnetic nanoparticle and an aptamer-modified upconversion nanoparticle were synthesised and used as a capture probe and a signal probe, respectively. The aptamer-modified magnetic nanoparticle, V. parahaemolyticus cell, and aptamer-modified upconversion nanoparticle formed a sandwich-like complex, which was rapidly separated from a complex matrix using a magnetic force, and the bacterial concentration was determined by fluorescence intensity analysis. The results showed that the fluorescence intensity signal correlated positively with the concentration of V. parahaemolyticus in the range of 3.2 × 102 to 3.2 × 105 CFU/mL, with a linear equation of y = 296.40x - 217.67 and a correlation coefficient of R2 = 0.9610. The detection limit of the developed method was 4.4 CFU/mL. There was no cross-reactivity with other tested foodborne pathogens. This method is highly specific and sensitive for the detection of V. parahaemolyticus, and can achieve the qualitative detection of this bacterium in a complex matrix.
Insights
A new aptamer-based detection method uses magnetic and upconversion nanoparticles for rapid identification of Vibrio parahaemolyticus. This highly sensitive technique accurately quantifies the foodborne pathogen in complex samples.
Area of Science:
- Biotechnology
- Nanotechnology
- Food Safety
Background:
- Vibrio parahaemolyticus is a prevalent, heat-labile, gram-negative bacterium causing foodborne illness, primarily from seafood.
- Accurate and rapid detection of V. parahaemolyticus is crucial for public health and food safety.
Purpose of the Study:
- To develop a sensitive and rapid detection method for the foodborne pathogen Vibrio parahaemolyticus.
- To utilize aptamer-modified nanoparticles for enhanced bacterial capture and signal detection.
Main Methods:
- Synthesis of aptamer-modified magnetic nanoparticles (capture probe) and upconversion nanoparticles (signal probe).
- Formation of a sandwich-like complex involving the nanoparticles and V. parahaemolyticus cells.
- Magnetic separation of the complex from complex matrices followed by fluorescence intensity analysis.
Main Results:
- A positive correlation was observed between fluorescence intensity and V. parahaemolyticus concentration (3.2 × 10^2 to 3.2 × 10^5 CFU/mL).
- The method demonstrated a low detection limit of 4.4 CFU/mL.
- High specificity was confirmed with no cross-reactivity against other foodborne pathogens.
Conclusions:
- The developed aptamer-nanoparticle based assay is highly specific and sensitive for detecting Vibrio parahaemolyticus.
- This method enables rapid qualitative detection of V. parahaemolyticus in complex food matrices.
