A Sliding Microfluidic Chip-Integrated Colorimetric Biosensor Using MnO₂ Nanoflowers for Rapid Salmonella Detection

Area of Science:

• Food safety and analytical chemistry
• Development of novel biosensing technologies
• Microfluidics and nanotechnology applications

Background:

• Current foodborne pathogen detection methods are often inefficient and complex.
• Rapid and sensitive screening is crucial for ensuring food safety.
• Need for user-friendly, on-site detection platforms.

Purpose of the Study:

• To develop a sliding microfluidic colorimetric biosensor for rapid, sensitive, and multiplex detection of Salmonella.
• To integrate multiple steps including capture, detection, and quantification onto a single microfluidic chip.
• To provide an efficient and user-friendly platform for foodborne pathogen analysis.

Main Methods:

• Utilized antibody-functionalized magnetic nanoparticles for specific Salmonella capture.
• Employed motor-assisted sliding for sequential introduction of reagents and sample processing.
• Incorporated manganese dioxide (MnO2) nanoflowers for signal amplification via a colorimetric reaction.
• Integrated mixing, separation, washing, catalysis, and detection within the microfluidic chip.

Main Results:

• Achieved a detection limit of 10 CFU/mL for Salmonella within 20 minutes.
• Demonstrated high accuracy in spiked pork samples with average recovery rates from 94.9% to 125.4%.
• Exhibited low variability with coefficients of variation between 4.0% and 6.8%.

Conclusions:

• The developed microfluidic biosensor is fast, sensitive, and user-friendly.
• The integrated platform shows significant potential for on-site detection of foodborne pathogens like Salmonella.
• This technology offers a promising advancement in food safety screening.