Sensory layers of poly(methyl metacrylate) for capacitive sensors for analysis of the content of heavy metal cations in water

The results of using poly(methyl methacrylate) coatings for the development of the capacitive sensors for analyzing the content of heavy metals in water (using Ni2+ ions as example) are presented. Structural and morphological characteristics of the formed conductive nickel layer and nanostructured poly(methyl methacrylate) films were studied by atomic force microscopy. Based on the analysis of the dependence of the capacitive characteristics of the original sensor on the frequency at different concentrations of Ni2+ ions, the following operating characteristics of the sensor were established: response time – 5 min; operating range of Ni2+ ion concentrations: 1 ‧ 10–3–50 mM; lower detection limit ≈ 0,06 mg/l. It is shown that the formation of a poly(methyl methacrylate) coating on a conductive nickel layer by the spin coating method increases the service life of the sensor to eight cycles while maintaining the level of sensor sensitivity.