Multimodal Microfluidic Biosensor With Interdigitated Electrodes (IDE) And Microelectrode Array (MEA) For Bacterial Detection And Identification

We demonstrate the integration of multiple sensing modalities for the first time onto a microfluidic platform to enable acquisition of multi-parameter data from bacterial cell cultures allowing for rapid detection and identification. The multimodal microfluidic biosensor consists of Interdigitated Electrodes (IDE) with an electrode pitch of 15 μm and a Microelectrode Array (MEA) having a dimension of 30 μm × 30 μm for impedance and electrophysiological measurements respectively. The impedance analysis of the bacterial cultures reveals time dependent growth dynamics, similar to traditional optical absorbance characterization. Additionally, impedance spectral fingerprinting allowed for the characterization of growth stages in Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) bacteria. The device has been fabricated using a union of makerspace and standard microfabrication technologies. Reliable microfluidic channel operations for 96 hours have been obtained with MEA impedance and phase characteristics (37.2 kΩ@1 kHz and -77°@1kHz) similar to those fabricated using conventional cleanroom based techniques.