Valorization of olive pruning lignocellulosic residues into carbon dots: A sustainable approach for discrimination of Iron species

<p dir="ltr">Herein, <u>carbon dots</u> (CDs) obtained from biochar of olive tree pruning residues (BC-OTPR) were synthesized at varying <u>pyrolysis</u> temperatures (500, 600, and 700 °C). The spectroscopic features of the CDs were further explored in the context of <u>metal ion </u>detection, specifically focusing on the discrimination of iron species. Significant <u>fluorescence quenching</u> upon interaction with iron (III), compared to iron (II) and other metal ions, was observed, indicating their potential as sensitive probes. In the presence of <u>hydrogen peroxide</u> and via the <u>Fenton</u> reaction, iron (II) was quantitatively oxidized into iron (III) – the determinable form, allowing for iron speciation. Synthesized CDs were analyzed using UV–Vis spectroscopy. <u>Transmission Electron Microscopy</u> (TEM) images revealed the uniform spherical morphology. Using the FT-IR analysis, transformation of <u>hemicellulose</u> and lignin present in the BC-OTPR into CDs with unique functionalities was corroborated. The CDs exhibited excitation-dependent fluorescence behavior, showcasing their potential for spectroscopic applications. Regression modeling was employed to investigate variables influencing iron detection. Notably, the CDs displayed linear behavior spanning over a range of 1.186 μM – 7.984 μM with a low limit of detection (LOD) of 0.5 μM of iron (III). Validation of precision and accuracy confirmed CDs' efficacy for analyzing food supplements and water samples.</p><h2>Other Information</h2><p dir="ltr">Published in: International Journal of Biological Macromolecules<br>License: <a href="http://creativecommons.org/licenses/by/4.0/" target="_blank">http://creativecommons.org/licenses/by/4.0/</a><br>See article on publisher's website: <a href="https://dx.doi.org/10.1016/j.ijbiomac.2025.144628" target="_blank">https://dx.doi.org/10.1016/j.ijbiomac.2025.144628</a></p>