Nanocomposites-based nitrated polyethersulfone and doped ZnYNiO for selective As³⁺ sensor application

The contamination of arsenic (As³⁺) cation in drinking water is one of the most well-known sources for human arsenic poison. Due to its high toxicity to human, there is a need to develop an efficient and low-cost method to detect it in aquatic environment. A sensor of nitrated polyethersulfone (PES-NO₂) doped with ZnYNiO nanocomposites was successfully fabricated. PES-NO₂ was synthesized in this study using H₂SO₄: HNO₃ while ZnYNiO nanoparticles were fabricated using wet-chemical technique under low temperature and basic condition. The results of Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analysis did confirm the interactions between the doped nanoparticles and nitro functions grafted on PES backbone. The developed polymeric nanocomposite (PES-NO₂-ZnYNiO) was then used as a superb coating sensor for As³⁺. The working electrode of desire heavy metal ion sensor was fabricated by glassy carbon electrode (GCE) coated with PES-NO₂-ZnYNiO nanocomposites as layer of thin film. To estimate the cationic sensor performances, a calibration curve obtained from current versus electrolyte (selective As³⁺ ion) concentration relation was plotted. The linearity of calibration curve is found over the linear dynamic range (LDR) of 0.1 nM~0.1 mM. The slope of calibration curve is used to measure the sensitivity and detection limit (DL) of As³⁺ cation sensor, and these are 9.8101 μA μM⁻¹cm⁻² and 96.77 ± 4.84 pM, respectively. Therefore, the As³⁺ ion sensor is found as selective with good sensitivity, reproducible with high accuracy, validated in real environmental samples, long-term stability in aqueous medium, and highly active with short response time.