Continuous and long-term monitoring of cellular and micro-organ activity is required for new insights intophysiology and novel technologies such as Organs-on-Chip. Moreover, recent advances in stem cell technologyand especially in the field of diabetes call for non-invasive approaches in quality testing of the large quantities ofsurrogate pancreatic islets to be generated. Electrical activity of such a micro-organ results in single cell actionpotentials (APs) of high frequency and in low frequency changes in local field potentials (slow potentials or SPs),reflecting coupled cell activity and overall organ physiology. Each of them is indicative of different physiologicalstages in islet activation. Action potentials in islets are of small amplitude and very difficult to detect. The use ofPEDOT:PSS to coat metal electrodes is expected to reduce noise and results in a frequency-dependent change inimpedance, as shown here. Whereas detection of high-frequency APs improves, low frequency SPs are less welldetected which is, however, an acceptable trade off in view of the strong amplitude of SPs. Using a dedicatedsoftware, recorded APs and SPs can be automatically diagnosed and analyzed. Concomitant capture of the twosignals will considerably increase the diagnostic power of monitoring islets and islet surrogates in fundamentalresearch as well as drug screening or the use of islets as biosensors.Read less <