Sensitivity-Tunable and Disposable Ion-Sensing Platform Based on Reverse Electrodialysis.

The detection of ions is of critical importance for environmental, industrial, and physiological applications, where sensitive and disposable ion sensing is still challenging. Herein, we present a sensitivity-tunable ion-sensing platform based on reverse electrodialysis, which is suitable for convenient and sensitive on-site analysis of various ions. It is revealed that this sensing system does not require any external power supply, and the sensitivities can be modulated by altering the number of stacks, possibly higher than the theoretical limitation, the Nernstian slope. The sensing system is integrated with a multicolor detection system via the introduction of polyaniline as a reporting material, which enables direct quantitative analysis based on a continuous color change gradient observable with the naked eye. Overall, the adopted approach by introducing reverse electrodialysis represents remarkable progress toward self-powered and disposable ion sensors with high and easily tunable potentiometric sensitivity.