k Carrageenan derived carbon dots for highly selective and sensitive detection of Fe3+ and oxytetracycline
Carbon dots (CDs) have received increasing attention as fluorescence sensors for the detection of different metal ions and organic small molecules. In this work, k carrageenan (k Carr) derived carbon dots (C CDs) were synthesized via a facile hydrothermal treatment with k Carr as a carbon source. The produced C CDs exhibited a high fluorescence with fluorescent quantum yield up to 20.6% and excellent fluorescent stability under diverse conditions (UV radiation, pH value and ionic strength) Then, the C CDs were utilized as dual functional sensing probe to detect both Fe3+ and oxytetracycline (Otc) The fluorescence intensity of C CDs was selectively quenched by Fe3+ in sharp contrast to dozens of other metal ions like Al3+ Ba2+ Ca2+ Co2+ Mg2+ Pb2+ Na+ Hg2+ Ni2+ Zn2+ Cd2+ and Cu2+ Coincidentally, this fluorescence could also be selectively quenched by Otc, entirely distinct from related physiological molecules like glycine, ammonium hydroxide, glucose, urea. The prepared C CDs could be used for label free sensitive and selective fluorescent detector for Fe3+ in a wide concentration range of 0 500 mM with a detection limit of 0.21 mM and for Otc as well in the range of 0 100 uM with a detection limit of 0.05 uM. Moreover, the fluorescent C CDs were successfully used for Fe3+ and Otc detection in some real samples, suggesting great application potential in fluorescence sensing of trace metal elements and antibiotics.
Journal of Materials Science