Charge Based Electrochemical Determination of Sulfide Ions in Water Samples Using Poly-L-Lysine Modified Electrode

Abstract

The sulfide ions are easily found in real water and waste water samples, whilst it can lead to personal distress owing to their toxic effects on aquatic life. Thus, the determination of sulfide ion S2− in environmental samples is much important for human health. Hence, we developed an electrochemical sensor for charge based electrochemical determination of sulfide ions in water samples using poly-L-lysine modified electrode. The sulfide ions can oxidize on the PLL-film by taking an advantage of charge based concentration of sulfide ions. The PLL-modified electrode was characterized by scanning electron microscope, Fourier transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy. The PLL modified electrode exhibits excellent electrocatalytic activity towards the detection of sulfide ions. In addition, the LSV performance of PLL modified electrode offers a lower detection potential, higher sensitivity and fast response towards the detection of sulfide ions. The linear concentration for sulfide ions determination ranges from 11.8–6663 μM with a detection limit of 2.65 μM was observed. The proposed sensor offers high selectivity in presence of various anions and cations. Besides, the PLL-modified electrode exhibits good recovery results for the detection of sulfide ions in different water samples.