Label-free impedimetric glycan biosensor for quantitative evaluation interactions between pathogenic bacteria and...

Area of Science:

• Biosensor Technology
• Microbiology
• Electrochemistry

Background:

• Understanding pathogenic mechanisms requires studying bacteria-host cell interactions.
• Selective recognition between pathogens and host cells is crucial for disease pathogenesis.
• Existing methods for analyzing these interactions can be time-consuming and complex.

Purpose of the Study:

• To develop a novel electrochemical impedance biosensor for detecting pathogenic bacteria.
• To characterize the binding affinity of the biosensor surface for specific bacterial strains.
• To evaluate the biosensor's potential for rapid and reliable pathogen detection.

Main Methods:

• Fabrication of a mannose/11-mercapto-11-acid/6-mercapto-hexanol/gold (Man/MUA-MH/Au) sensing surface.
• Characterization of bacterial capture capacity using Electrochemical Impedance Spectroscopy (EIS).
• Analysis using Randles equivalent circuit and Frumkin isotherm model to determine binding affinity.

Main Results:

• The Man/MUA-MH/Au surface demonstrated good biological activity and stability.
• Higher binding affinity was observed for Salmonella Typhimurium ATCC14028 (K_ADS = 2.16 × 10⁶ CFU/mL).
• A linear relationship was found between normalized impedance and bacterial concentration (R² = 0.96) with a detection limit of 50 CFU/mL.

Conclusions:

• The developed electrochemical impedance biosensor is rapid and reliable for studying pathogen-glycan interactions.
• The biosensor shows promise as a point-of-care diagnostic tool for evaluating bacterial pathogenicity.
• This technology facilitates a deeper understanding of infectious disease mechanisms.