Label-Free Electrochemical Sensor for Rapid Bacterial Pathogen Detection Using Vancomycin-Modified Highly Branched...

Area of Science:

• Biomedical Engineering
• Biosensor Technology
• Microbiology

Background:

• Antimicrobial resistance necessitates rapid bacterial diagnostics.
• Current methods for bacterial detection can be time-consuming.
• Point-of-care testing is crucial for reducing antibiotic misuse.

Purpose of the Study:

• To develop a rapid, label-free sensor for Gram-positive bacteria detection.
• To utilize vancomycin-modified polymers and electrochemical impedance spectroscopy (EIS).
• To enable direct detection of bacterial binding events.

Main Methods:

• Immobilization of vancomycin-modified highly branched polymers on gold screen-printed electrodes.
• Detection of Gram-positive bacteria via polymer conformation changes using EIS.
• Quantification of polymer changes with pre- and post-incubation EIS measurements.

Main Results:

• Direct, label-free detection of *Staphylococcus carnosus* within 20 minutes.
• Concentration-dependent signal changes observed for *S. carnosus* (OD₆₀₀ 0.002–0.1).
• Clear discrimination between Gram-positive (*S. carnosus*) and Gram-negative (*E. coli*) bacteria.
• Demonstrated good storage and operational stability of the sensor.

Conclusions:

• The developed sensor offers a simplified and rapid approach for bacterial detection.
• This technology has the potential to reduce diagnostic complexity and improve patient outcomes.
• The sensor advances point-of-care diagnostics for bacterial infections, aiding antimicrobial stewardship.