A Triphenylamine-Functionalized Silica Nanoparticle for Fluorescent Detection of Fe2+/Fe3+ in Red Wine

Iron plays a crucial role in numerous physiological processes; however, both iron deficiency and iron overload can lead to severe health disorders, including anaemia, organ dysfunction, neurodegenerative diseases, and cancer. Therefore, the development of rapid, sensitive, and reliable sensing platforms for iron ion detection has attracted considerable attention in recent years. In this study, a novel triphenylamine-functionalized silica nanoparticle probe ( TPA–SNP ) was developed for the selective and sensitive detection of Fe²⁺ and Fe³⁺ ions. The sensing platform combines the strong fluorescence properties and electron-donating characteristics of triphenylamine with the enhanced stability provided by silica nanoparticles. In addition, the incorporation of thiophene units contributes to efficient π-conjugation and charge transfer, improving the optical performance of the system. The synthesized TPA–SNP probe exhibited a rapid fluorescence “turn-off” response toward Fe²⁺/Fe³⁺ ions with high selectivity and sensitivity over a broad pH range. Finally, the efficient determination of total iron in red wine samples demonstrates the practical applicability of the method without the need for specialized equipment.