An efficient DNAzyme-based DNA scaffold for label-free and sensitive bacterial pathogen detection

Area of Science:

• Biotechnology
• Analytical Chemistry
• Molecular Diagnostics

Background:

• Detecting low levels of bacterial pathogens like Staphylococcus aureus (S. aureus) in clinical samples, such as dental implants, remains challenging.
• Sensitive and label-free detection methods are crucial for timely and accurate diagnosis of bacterial infections.

Purpose of the Study:

• To develop an efficient scaffold for sensitive and label-free detection of Staphylococcus aureus (S. aureus).
• To establish a signal amplification strategy for improved bacterial detection limits.

Main Methods:

• Construction of a detection scaffold involving self-assembly of DNA chains (Chain i, ii, iii) and DNAzyme activity.
• Utilizing DNA polymerase for signal amplification and a cyclic process for enhanced detection.
• Employing Thioflavin T (ThT) as a fluorescent reporter triggered by bacterial binding and DNAzyme cleavage.

Main Results:

• The developed scaffold achieved sensitive, label-free detection of S. aureus.
• Demonstrated a wide detection range from 10^2 to 10^6 CFU/mL.
• Achieved a low limit of detection of 45 CFU/mL.

Conclusions:

• The novel DNAzyme-based scaffold offers a promising approach for the sensitive and rapid diagnosis of bacterial infections.
• The label-free and signal-recycling mechanism enhances detection efficiency for Staphylococcus aureus.
• This method holds potential for improving clinical diagnostics, particularly for challenging sample types.