A reusable and reagent-free solid-state sensor for chloride detection

Chloride homeostasis is required for multiple human body functions including metabolism, fluid and electrolyte balance. Electrochemical sensors are used for chloride measurements due to their rapid response, small size and easy to use. Here, we have demonstrated a solid-state chloride sensor using a chemically pretreated silver wire that can be fabricated in low-resource settings. The sensors exhibited a calibration slope of -57.6mV/decade within a measuring range of 10 mM to 260 mM chloride concentrations and an R ² value of 0.9989. The sensor did not show any significant interference from common coexisting compounds like sulphate, carbonate, lactic acid and urea. The dynamic sensor response did not change significantly within pH change from pH6.5 to pH7.4. The sensor does not show any significant change in the response till 5 days (standard deviation <0.2% of sensor response).