Coordination-induced suppression of non-radiative decay in carbon dots: A novel fluorescent-enhancement sensor for sensitive and selective determination of Al3+ in pharmaceutical samples.

Excessive intake of aluminum ions (Al3+) has been associated with significant health risks. Therefore, the development of simple, accurate, and reliable methods for the determination of aluminum content in pharmaceutical products is critical for drug quality control and patient safety. Herein, we report a novel type of fluorescent carbon dots (Suc-CDs) synthesized from sucrose and anhydrous ethanol via a one-pot solvothermal treatment, and their development into a fluorescent-enhancement sensor for Al3+. The highly selective fluorescence enhancement of the Suc-CDs toward Al3+ is supported by a sensing model dominated by suppression of non-radiative decay, while the available spectroscopic evidence is consistent with contributions from inhibited photoinduced electron transfer and reduced surface defect-state trapping. Under optimized conditions, the sensor exhibits a relatively wide linear range of 5.0-80 μM for Al3+ with a detection limit as low as 1.49 μM. Furthermore, the sensor was successfully applied to the determination of the active pharmaceutical ingredient in Compound Aluminium Hydroxide Tablets and was evaluated by spike-recovery experiments in Mannitol Injection, with recoveries and precision meeting the acceptance criteria cited in this study. Consequently, this study provides a new strategy for simple, cost-effective, and reliable fluorometric detection of Al3+ for broader application scenarios.