Development of a disposable microfluidic biochip for multiparameter cell population measurements.

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.