Quantitative Determination of Staphylococcus aureus Using Aptamer-Based Recognition and DNA Amplification Machinery

Area of Science:

• Biosensor technology
• Nanotechnology
• Food safety

Background:

• Staphylococcus aureus (S. aureus) is a prevalent foodborne pathogen posing risks to public health.
• Sensitive detection methods are crucial for monitoring S. aureus contamination in food and environmental settings.

Purpose of the Study:

• To develop a novel and highly sensitive biosensor for detecting Staphylococcus aureus (S. aureus).
• To create a detection platform utilizing aptamer recognition, DNA walkers, and rolling circle amplification (RCA).

Main Methods:

• Designing DNA duplexes with aptamers for S. aureus identification on an electrode surface.
• Employing a DNA walker mechanism and rolling circle amplification (RCA) to form DNA nanoflowers.
• Converting aptamer-S. aureus binding events into amplified electrochemical signals.

Main Results:

• The biosensor demonstrated a linear response range from 60 to 6 x 10^7 CFU/mL for S. aureus.
• Achieved a remarkably low detection limit of 9 CFU/mL for S. aureus.
• Successfully generated a unique DNA nanoflower structure for signal amplification.

Conclusions:

• The developed aptamer-based biosensor offers a sensitive and effective method for detecting S. aureus.
• The DNA nanoflower formation amplifies the electrochemical signal, enabling low-level pathogen detection.
• This technology holds promise for monitoring S. aureus contamination in food and environmental samples.