| Summary: | This study used a thiolated calix[4]arene derivative modified on gold nanoparticles and a screen-printed carbon electrode (TC4/AuNPs/SPCE) for Pb<sup>2+</sup> and Cu<sup>2+</sup> determination. The surface of the modified electrode was characterised via Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Differential pulse voltammetry (DPV) was used for the detection of Pb<sup>2+</sup> and Cu<sup>2+</sup> under optimum conditions. The limit of detection (LOD) for detecting Pb<sup>2+</sup> and Cu<sup>2+</sup> was 0.7982 × 10<sup>−2</sup> ppm and 1.3358 × 10<sup>−2</sup> ppm, respectively. Except for Zn<sup>2+</sup> and Hg<sup>2+</sup>, the presence of competitive ions caused little effect on the current response when detecting Pb<sup>2+</sup>. However, all competitive ions caused a significant drop in the current response when detecting Cu<sup>2+</sup>, except Ca<sup>2+</sup> and Mg<sup>2+</sup>, suggesting the sensing platform is more selective toward Pb<sup>2+</sup> ions rather than copper (Cu<sup>2+</sup>) ions. The electrochemical sensor demonstrated good reproducibility and excellent stability with a low relative standard deviation (RSD) value in detecting lead and copper ions. Most importantly, the result obtained in the analysis of Pb<sup>2+</sup> and Cu<sup>2+</sup> had good recovery in river water, demonstrating the applicability of the developed sensor for real samples.
|
|---|