Choice of Reference Electrode is Critical for Potentiometric Whole Cell‐based Sensor

Cells have a net negative outer charge which gives rise to a potential difference in a potentiometric set up. Here, Triton X‐100 was used as a model toxin and the cell death was monitored by the potential change, noticed as decrease in negativity. Hence, cytotoxicity can be tested in vitro and real‐time using potentiometry. However, silver ions (Ag⁺) and/or silver chloride ions (AgCl₂)^?1 lead to cell death when we used the standard Ag/AgCl reference electrode with 3 M NaCl as filling solution. Our further experimentation showed that PBS as filling solution was biocompatible and also gave stable potentiometric profiles.