Sodium-Polyacrylate-Based Electrochemical Sensor for Highly Sensitive Detection of Gaseous Phenol at Room Temperature.

The detection of volatile organic compounds with electrochemical gas sensors is still very challenging regarding their sensitivity, selectivity, and operation at room temperature. There is a need for robust, sensitive, inexpensive, and yet easy-to-operate sensors for phenol and other phenolic compounds that would function reliably under ambient conditions. Herein, we present a phenol gas sensor based on a combination of a semi-solid, alkaline sodium polyacrylate and commercial screen-printed electrodes. Sodium polyacrylate was employed as a multi-functional sensing material serving as a (i) gel-like electrolyte, (ii) accumulation milieu, and (iii) derivatization medium. Under ambient conditions, the sensor showed excellent sensitivity in the low ppbv (μg m⁻3) range, a good linear operation in the examined concentration range of 0.1‒1.0 ppmv, and low sensitivity toward examined interferences. The sensor also indicated a possibility to differentiate between several phenolic compounds based on their oxidation potential. Given its favorable electroanalytical performance, a strong application potential is envisioned in topical fields such as environmental monitoring, cultural heritage preservation, and occupational health and safety.