A Specific and Sensitive Aptamer-Based Digital PCR Chip for Salmonella typhimurium Detection

Area of Science:

• Food safety and public health
• Biosensor technology
• Molecular diagnostics

Background:

• Foodborne illnesses caused by Salmonella typhimurium (S. typhimurium) present significant public health and food safety challenges.
• Detecting S. typhimurium in complex food matrices requires rapid, sensitive, and quantitative methods.
• Current detection methods face limitations due to sample complexity and sensitivity requirements.

Purpose of the Study:

• To develop an integrated biosensor for the specific detection, identification, and quantification of S. typhimurium in food samples.
• To create a rapid and ultra-sensitive platform for on-site monitoring of foodborne pathogens.
• To demonstrate the potential of aptamer-based capture and digital PCR for improved pathogen detection.

Main Methods:

• Utilized aptamer-coated magnetic beads (Apt-MBs) for selective capture and concentration of S. typhimurium.
• Developed a self-priming chip-based digital PCR system for on-site detection and quantification.
• Integrated Apt-MBs with the digital PCR chip to create a lab-on-a-chip biosensor.

Main Results:

• Achieved specific capture and detection of S. typhimurium cells as low as 90 CFU/reaction with 94.5% capture efficiency.
• The integrated biosensor provided rapid results, with the entire process completed in approximately 2 hours.
• The platform demonstrated robustness and did not require external power for sample loading.

Conclusions:

• The developed Apt-MBs combined with chip-based digital PCR offers a powerful, integrated solution for on-site foodborne pathogen monitoring.
• This platform enables highly specific and sensitive detection and quantification of S. typhimurium.
• The technology holds potential for monitoring other bacteria and for future point-of-care testing applications.