Dielectrophoretic Enrichment Coupled with Impedance Spectroscopy for Real-Time Bacterial Detection and Antibiotic...

Area of Science:

• Biomedical Engineering
• Microfluidics
• Biosensing

Background:

• Antimicrobial resistance (AMR) necessitates faster bacterial detection and antibiotic susceptibility testing (AST).
• Conventional culture-based methods for AST are time-consuming.
• Existing diagnostic tools often lack the speed and sensitivity required for timely clinical decisions.

Purpose of the Study:

• To develop and validate a real-time, label-free interdigitated wave electrode array (IWEA) platform.
• To integrate dielectrophoretic (DEP) enrichment with impedance spectroscopy for enhanced bacterial analysis.
• To enable rapid bacterial detection and AST for Gram-positive and Gram-negative bacteria.

Main Methods:

• Design and optimization of an IWEA using COMSOL Multiphysics for improved electric-field strength.
• Utilizing dielectrophoretic (DEP) preconcentration for bacterial enrichment.
• Employing impedance spectroscopy to monitor bacterial responses to antibiotics.

Main Results:

• Sensitive detection of *Staphylococcus aureus* and *Escherichia coli* from 10 to 10⁵ CFU/mL within 30 minutes.
• Successful differentiation of antibiotic-susceptible and resistant bacterial strains using impedance variations.
• Validation of AST results through Scanning Electron Microscopy (SEM) imaging and disk diffusion assays.

Conclusions:

• The IWEA platform provides a rapid, label-free, and quantitative method for bacterial detection and AST.
• This technology shows significant potential for antimicrobial screening and point-of-care diagnostics.
• The developed IWEA system addresses the critical need for faster diagnostics in combating AMR.