Real-Time Bacterial Monitoring and Drug Screening Using the Interdigitated Wave-Shaped Biosensor (IWE), Combined with FEM and Molecular Docking Studies

Rapid and accurate detection of bacteria in water, food, and air is essential for protecting public health, especially amid rising antimicrobial resistance and outbreaks. Traditional detection methods, while reliable, are time-consuming, resource-intensive, and unsuitable for real-time monitoring. Similarly, antibiotic efficacy assessment requires laborious culturing, delaying treatment. This study presents an interdigitated wave-shaped electrode (IWE) capacitance biosensor for real-time bacterial monitoring and drug evaluation. The IWE, optimized via COMSOL simulations addresses edge effects and enhances electric field uniformity and capacitance sensitivity. Simulated capacitance in PBS (5.21 × 10^-7 F at 1 Hz) closely matched the experimental value (3.19 × 10^-7 F at 1 Hz), validating the optimized IWE design. Integrated with a 16-channel multiplexer, the biosensor enabled high-throughput, real-time detection of <i>Staphylococcus aureus</i>, <i>Bacillus cereus</i>, and <i>Escherichia coli</i> over a range of 10 to 10⁴ CFU/mL, with a detection limit of 10 CFU/mL. Molecular docking simulations were employed to assess antibiotics, which were subsequently tested through real-time capacitance measurements. A decrease in the capacitance indicated effective bacterial inhibition at concentrations exceeding the minimum inhibitory concentration. Results were further validated through disk diffusion assays and scanning electron microscopy, confirming the accuracy. This integrated approach demonstrates the biosensor's potential for real-time pathogen detection and antimicrobial susceptibility assessment.