Accurate cadmium (II) detection with single crystalline α-Fe₂O₃ nano-hexagonal modified screen-printed carbon electrode

Even in small concentrations, toxic metals like lead, cadmium, and mercury are dangerous to the environment and human health. Environmental monitoring depends on precisely identifying these heavy metals, particularly cadmium ions (Cd(II)). In this study, we present a novel screen-printed carbon electrode (SPCE) modified with single crystalline α-Fe₂O₃ nano-hexagons that functions as a sensor for detecting Cd(II). The performance of the fabricated sensor was thoroughly assessed and compared with unmodified SPCE using the voltammetric method. The crystalline structure of the synthesized α-Fe₂O₃ nano-hexagons was confirmed through XRD, and surface analysis revealed an average diameter and thickness of 86 nm and 9 nm, respectively. The α-Fe₂O₃ modified SPCE yields a 7-fold enhanced response (at pH 5.0 vs. Ag/AgCl) to Cd(II) than bare SPCE. The modified electrode effectively detects Cd(II) with a linear response range of up to 333.0 µM and a detection limit of 0.65 nM under ideal circumstances. This newly fabricated sensor offers significant potential for environmental monitoring applications by providing outstanding practicality, anti-interference ability, and repeatability for detecting Cd(II) in water samples.