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. [ABSTRACT FROM AUTHOR]