A fluorescent aptasensor for Staphylococcus aureus based on strand displacement amplification and self-assembled DNA...

Area of Science:

• Biotechnology
• Biosensing
• Molecular Diagnostics

Background:

• Staphylococcus aureus (S. aureus) is a significant pathogen in healthcare and food industries.
• Accurate and rapid detection methods for S. aureus are crucial for public health.
• Existing detection methods can be time-consuming or lack sensitivity.

Purpose of the Study:

• To develop a highly sensitive and specific fluorescent aptasensor for S. aureus detection.
• To integrate strand displacement amplification (SDA) with DNA self-assembly for signal amplification.
• To validate the aptasensor's performance in complex matrices like milk samples.

Main Methods:

• Design of an S. aureus aptamer-based fluorescent aptasensor.
• Utilizing magnetic beads for immobilization and separation.
• Employing strand displacement amplification (SDA) for signal amplification.
• Formation of a DNA hexagonal structure for fluorescence signal generation.
• Detection using SYBR Green I staining and fluorescence spectroscopy.

Main Results:

• The aptasensor demonstrated a broad linear detection range from 7 to 7 x 10^7 CFU/mL.
• Achieved a low detection limit of 1.7 CFU/mL for S. aureus.
• Exhibited high specificity with negligible response to other bacterial species.
• Successfully detected S. aureus in spiked milk samples, showing practical applicability.

Conclusions:

• The developed aptasensor offers a sensitive, specific, and rapid method for S. aureus detection.
• The combination of SDA and DNA self-assembly provides a robust platform for biosensing.
• This technology holds promise for food safety control and clinical diagnostics.