Sensitivity and selectivity sensing cadmium(II) using amination functionalized porous SnO₂ nanowire bundles-room temperature ionic liquid nanocomposite: Combined efficient cation capture with control experimental conditions

Electrochemical analytical challenge for cadmium(II) [Cd(II)] determination is to seek an efficient platform to realize the sensitive and selective detection. Herein, a sensing interface for the detection of Cd(II) was designed and constructed by the amination treated porous SnO₂ nanowire bundles-room temperature ionic liquid nanocomposite (NH₂/SnO₂-RTIL). Through the delicate control of experimental conditions (deposition potential and electrolyte pH), the excellent sensitive and selective electroanalysis of ultra-trace Cd(II) was achieved using square wave anodic stripping voltammetry (SWASV). The NH₂/SnO₂-RTIL uses its efficient capture during the Cd(II) deposition step to enhance the sensitivity of the stripping response. Under the optimal experimental conditions, the NH₂/SnO₂-RTIL nanocomposite offered direct detection of Cd(II) within the desirable range (0.0267 μM) in drinking water as specified by the World Health Organization (WHO), a limit of detection (3σ method) of 0.0054 μM with a sensitivity of 124.03 ± 3.75 μA μM⁻¹ was obtained in the presence of common heavy metal ions. Finally, the analytical application of the proposed method toward the detection of Cd(II) in a real water sample collected from Wangxiaoying sewage treatment plant, Hefei City, China, has been successfully verified.