Fluorimetric and Ratiometric Probes Based on Carbon Nanomaterials Derived from the Brewing Industry Waste for Iron(III) Ion Detection in Aqueous Environments

In this study, fluorescent probes were developed using carbon nanodots (CNDs) derived from hydrochar obtained through the hydrothermal carbonization of beer bagasse. Beer bagasse is a by-product of the beer industry and offers several advantages as a lignocellulosic source for carbon material synthesis. The raw materials and the resulting CNDs were characterized using various techniques. The synthesized CNDs displayed small dimensions, intriguing fluorescence behaviour, high stability, and remarkable water solubility due to the presence of hydroxyl and carboxyl functional groups. Leveraging these properties, the CNDs were utilized in the development of highly sensitive fluorimetric probes for iron ions, exhibiting a high response and low limit of detection.