Resistive Method for Bacterial Detection Employing a Silicon Nanowire Electrical Chip

There is now an urgent need to develop reliable, rapid, and cost-effective methods for bacterial detection, particularly for point-of-care applications. This study explores the unique properties of silicon nanowire (SiNW) arrays as a resistive sensing platform for detecting Listeria innocua. Vertically aligned SiNWs, fabricated via metal-assisted chemical etching, exhibited high sensitivity to bacterial adsorption. Conductance measurements revealed a more than 10-fold increase as bacterial concentrations rose from 10⁵ to 10⁷ CFU/mL, with clear saturation at higher levels. The study employed both direct current (DC) and alternating current (AC) methodologies, with AC conductance consistently outperforming DC due to reduced potential barrier effects. An equivalent circuit model was developed to describe the impedance behavior of the SiNW-bacteria system, offering valuable insights into charge transport mechanisms. These results demonstrate the potential of SiNW-based sensors as robust, scalable, and high-performance diagnostic tools. Beyond bacterial detection, the proposed platform offers promising applications in clinical diagnostics, environmental monitoring, and food safety.