Spectrofluorometric determination of Fe3+, Pd2+, and Sn2+ ions using carbon nanodots derived from hazelnut shells

OpenAlex İngilizce

Abstract Carbon nanodots (CNDs) were synthesized from hazelnut shells using the pyrolysis method in an oven at temperatures ranging from 250 to 400 °C and reaction times between 1 and 3 h. The structural and optical properties of the CNDs, which exhibited strong blue fluorescence under a UV lamp (365 nm), were characterized using UV–vis absorption spectroscopy, fluorescence spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The quantum yield of the CNDs was determined to be between 2.2% and 7.8%. The effect of various cations on the fluorescence spectra of the CNDs was investigated using fluorescence spectrometry. Among the synthesized CNDs, those prepared via pyrolysis for 3 h at 300 °C, 315 °C, and 350 °C (designated as HS300-3, HS315-3, and HS350-3, respectively) exhibited selective fluorescence quenching in the presence of Fe3+, Sn2+, and Pd2+. These CNDs were applied for the determination of Fe3+ in tap water and soil samples, while HS315-3 was also employed for the detection of Sn2+ and Pd2+ in tap water. The limits of detection (LOD) were 4.5 μg l−1 for Fe3+ and 15.8 μg l−1 for both Sn2+ and Pd2+. The accuracy of the methods was validated through spiked recovery experiments with tap water samples and by analyzing a certified reference material (CRM-SA-C Sandy Soil C).