A red fluorescent carbon dots with good water solubility for rapid detection of Al³⁺ in actual samples

We developed a facile strategy for the fabrication of red fluorescent carbon nanodots (R-CDs) and demonstrated their applications for Al³⁺ sensing. Red-emission carbon dots (CDs) were synthesized using a simple hydrothermal treatment with citric acid and urea as precursors, manifesting intriguing red-emission behaviour at 610 nm. With increasing Al³⁺ concentration, the fluorescence band at 610 nm decreased gradually. Monitoring the intrinsic fluorescence variation (I_610nm ), as-prepared CDs were developed as an effective platform for fluorescent Al³⁺ sensing, with a linear range of 0.5-60.0 μM and a detection limit of 3.0 nM. More importantly, R-CDs have been applied successfully to the analysis of Al³⁺ in actual samples with satisfactory recoveries in the range 97.12-102.05%, which indicated that obtained CDs could be implemented as an effective tool for the identification and detection of Al³⁺ in actual samples.