Development of a Disposable Microfluidic Biochip for Multiparameter Cell Population Measurements

Abstract

An under recognized cause of preventable mortality is healthcare-associated (nosocomial) infections such as biofilms found on implants and catheters. About 5% of U.S. and E.U. patients acquire nosocomial infections leading to prolonged hospitalization, increased patient suffering, and mortality rates. To date, no satisfactory solutions are available to monitor biofilm formation under near-native conditions. As a consequence, in the present work, we report the development of a disposable microfluidic biochip capable of continuously monitoring cell population dynamics under physiological shear force conditions. We demonstrate the simultaneous application of contactless bioimpedance spectroscopy and amperometric measurements to monitor fungal biofilm growth rates and metabolic activities. Quantitative cell analysis is accomplished by the use of high-density interdigitated capacitors (microIDC) isolated by a 700 nm epoxy (SU-8 resist) based passivation layer to noninvasively assess biofilm formation in predefined proliferation chambers. Additionally, biofilm respiration activity is measured using redox-mediators oxidized at band electrodes located downstream within microchannels. The disposable biofilm analysis platform is used to continuously monitor the dynamic responses of C. albicans to different glucose and galactose concentrations.

Use of Single-Frequency Impedance Spectroscopy to Characterize the Growth Dynamics of Biofilm Formation in Pseudomonas aeruginosa

“…Gottschamel et al . found that contactless bioimpedance measurements are particularly sensitive toward capacitive changes during biofilm formation and maturation 58 . Kim et al .…”

Direct electrochemical determination of Candida albicans activity

“…Junil 2012). In bioelectrochemical systems, either the direct interaction between microorganisms and electrodes can be used, or the microbe-electrode communication can be induced with natural (Wang, Tsujimura et al 2007) or artificial redox mediators (Roller SD 1984;Heiskanen A 2004;Gottschamel, Richter et al 2009). Electrochemical detection methods that are based on redox mediators are applicable when the reduced electron acceptor can be oxidized at electrodes (K. Junil 2012;Congdon, Feldberg et al 2013).…”

New Trends in Impedimetric Biosensors for the Detection of Foodborne Pathogenic Bacteria

“…Gottschamel et al [88] developed a disposable microfluidics biochip for multiparameter Candida albicans population measurements, which can monitor Candida albicans growth rates and metabolic activities by simultaneous bioimpedance spectroscopy and amperometric measurements. Zhu et al [92] used fluidic electrodes to fabricate a microfluidics device for detecting bacterial cells in deionized water suspensions with a detection limit of 10 3 cfu·mL −1 .…”