This paper presents a feasibility study on the integration of multiple biosensors based on amperometric, potentiometric, and impedimetric detection techniques, as well as physical sensors on a single chip. The sensor chip comprises six sensors for in-situ monitoring of important process parameters in a bioprocess: glucose, lactate, pH, cell density, dissolved oxygen concentration, and temperature. The wafer-level parallel fabrication process of multiple microsensors on a single substrate involves four relatively simple processes. The fabricated enzyme sensors were tested with a linear working range up to a concentration of 10 mM for the glucose and lactate sensors and show a fast response time of 20 s. The integrated pH sensor was governed by a near-Nernstian equation with a sensitivity of 60.8 ± 2.4 mV/pH. Cell density, dissolved oxygen, and temperature sensor were also electrically tested. Results obtained from experimental measurements can be considered a promising step towards the realization of a real-time and parallel in-situ measurement platform for bioprocesses.
