Real-time monitoring of single-cell extracellular pH based on stretchable microelectrode array.

The study of cell mechanics was significant for understanding cellular physiological functions, the mechanisms of disease occurrence, and the development of novel therapeutic approaches. However, research on the mechanism of mechanical strain action at the single-cell level was relatively lacking. Herein, we developed a serpentine stretchable sensor array capable of exerting precise mechanical strain on cells and monitoring extracellular pH (pHe) changes at single cell level. The PANI sensor array based on the serpentine structure exhibited good electrochemical stability against mechanical deformation enabling accurate measurement of pHe in single-cell during stretching. The results showed that mechanical stimulation induced cells to undergo deformation, thereby promoting increased cell acid excretion. Both stretching and compressive deformation were able to promote the increase of cell acid excretion. This sensor served as a powerful tool for researching the effect of cellular mechanics on cell metabolism at the single-cell level.