Enhanced electrochemical detection of nitrite ions by CTAB-modified hexagonal Fe-doped SnS2 nanosheets in water

Nitrite ions originate from various natural and anthropogenic sources and can cause health issues including methemoglobinemia and potential carcinogenic effects. As the nitrite in water has become an increasing threat to human health, the accurate evaluation of nitrite is urgently needed for environmental quality and safety management. In this paper, we designed a CTAB/SF5/GCE sensor, which exhibited an obvious enhancement compared to the pristine glassy carbon electrode (GCE). The morphology characterization confirmed the hexagonal nanosheets of SnS₂ and the even distribution of Fe element. The energy band, Tafel plots, and EIS spectroscopy were employed to investigate the enhancement mechanism, demonstrating that improving charge transfer on the sensing interface is crucial in enhanced signals. Cyclic voltammetry (CV) was adopted as the electrochemical method to measure the nitrite in water and a sensitivity of 0.129 μA·μM⁻¹ was exhibited in the range of 30–500 μM, and the limit of detection (LOD) was calculated to be 6.51 μM. The reliability including the repeatability, reproducibility, and stability of this sensor were estimated and showed satisfactory results. The test in real samples and the assessment of interfering substances showed the CTAB/SF5/GCE possesses a large potential in the practical application of electrochemical sensing of nitrite.