Study of Real-Time Spatial and Temporal Behavior of Bacterial Biofilms Using 2-D Impedance Spectroscopy

Abstract

STUDY OF REAL-TIME SPATIAL AND TEMPORAL BEHAVIOR OF BACTERIAL BIOFILMS USING 2D IMPEDANCE SPECTROSCOPYThe study of biofilms and their effect on disease treatment, prevention, and cures has been increasing in importance in recent years. Bacterial biofilms are colony formations developed by bacteria that allow them to anchor onto a surface and survive hostile environments. The formation of harmful bacteria biofilms on some surfaces can be troublesome, particularly in the case of medical implants.The continuing rise of antibiotic resistant bacteria over the past decade had escalated the need to study and understand biofilms. This thesis presents the design of a multi-channel impedance spectroscopy instrument to allow 2D spatial and temporal evaluation of biofilm growth. The custom-designed circuits allow measurement updates once per second on the entire set of impedance sensors. The distance between the neighboring sensors is 220 micrometers, allowing realtime observation of biofilm growth. The initial results show that the proposed 2D impedance spectroscopy tool provides the needed accuracy to predict the existence of bacteria biofilm at a given sensor location. The initial results were validated using optical images with fluorescent staining.

Impedance Imaging of Cells and Tissues: Design and Applications

“…Impedance-based detection with MEAs has been used to monitor the growth and distribution of biofilms on electrode arrays [ 65 ], to detect the hybridization of DNA strands that have been previously attached to the sensor surface [ 10 , 66 , 67 ], and to measure the dynamic attachment and micromotions of cells [ 11 ]. A notable example of using MEAs for real-time imaging of adherent cells is the work of Laborde et al, where the authors presented a CMOS high-density microelectrode array (HD-MEA) with 65,536 electrodes of 90nm radius on a 0.6 μ m × 0.89 μ m grid [ 11 ].…”

CMOS electrochemical imaging arrays for the detection and classification of microorganisms

“…It is also possible to use EIS to monitor the growth of adherent cells on surfaces [3], [26]- [29], or to estimate the surface coverage of bacterial biofilms [30]. At larger dimensions, this approach has been commercialized in impedance-based cell culture monitoring systems, which use millimeter-scale interdigitated electrodes [26].…”

CMOS Electrochemical Imaging Arrays for the Detection and Classification of Microorganisms

“…It is also possible to use EIS to monitor the growth of adherent cells on surfaces [3], [26]- [29], or to estimate the surface coverage of bacterial biofilms [30]. At larger dimensions, this approach has been commercialized in impedance-based cell culture monitoring systems, which use millimeter-scale interdigitated electrodes [26].…”