Abstract
In this study we present the development and the characterization of a generic platform for cell culture able to monitor extracellular ionic activities (K
+
, NH
4
+
) for real-time monitoring of cell-based responses, such as necrosis, apoptosis or differentiation. The platform for cell culture is equipped with an array of 16 silicon nitride micropipette-based ion-selective microelectrodes with a diameter of either 2 or 6 μm. This array is located at the bottom of a 200 μm wide and 350 μm deep microwell where the cells are cultured. The characterization of the ion-selective microelectrode arrays in different standard and physiological solutions is presented. Near Nernstian slopes were obtained for potassium- (58.6 ± 0.8 mV/pK, n=15) and ammonium-selective microelectrodes (59.4 ± 3.9 mV/pNH
4
, n=13). The calibration curves were highly reproducible and showed an average drift of 4.4 ± 2.3 mV/h (n=10). Long-term behavior and response after immersion in physiological solutions are also presented. The lifetime of the sensors was found to be extremely long with a high recovery rate.