This paper describes the design and characterization of a silicon-based sensor chip for monitoring of fermentation processes. The sensor chip consists of three sensors using different transducer principles. A capacitive electrolyteinsulator-semiconductor (EIS) field-effect structure with Ta 2 O 5 as gate material was utilized as pH sensor. An electrolyte conductivity sensor was realized by measuring the impedance between two interdigitated electrodes (IDE). A platinum thermistor was included for temperature measurements. The EIS sensor was integrated into a bioreactor and successfully used for an inline pH measurement. The layout of the IDE has been optimized with respect to a high cell constant and a wide detectable conductivity range. The integrated platinum thermistor allowed for temperature compensation of the electrolyte conductivity measurement.

The metabolic activity of Chinese hamster ovary (CHO) cells was observed using a light‐addressable potentiometric sensor (LAPS). The dependency toward different glucose concentrations (17–200 mM) follows a Michaelis–Menten kinetics trajectory with Km = 32.8 mM, and the obtained Km value in this experiment was compared with that found in literature. In addition, the pH shift induced by glucose metabolism of tumor cells transfected with the HPV‐16 genome (C3 cells) was successfully observed. These results indicate the possibility to determine the tumor cells metabolism with a LAPS‐based measurement device.

No abstract