Nitrogen and phosphorus dual-doped carbon dots as a label-free sensor for Curcumin determination in real sample and cellular imaging.

A nitrogen and phosphorus dual-doped carbon dots (NP-Cdots) was fastly synthesized with glucose as the carbon source, 1,2-ethylenediamine as N-dopant and concentrated phosphoric acid as P-dopant. The as-synthesized NP-Cdots was utilized as a label-free sensor for determination of Curcumin (Cur). The proposed NP-Cdots-based fluorescence sensor was applied for sensitive detection of Cur in aqueous solution, achieving a linear range of 0.5-20 µmol/L and a detection limit of 58 nmol/L (21.37 ng/mL). The common amino acids and other drugs do not interfere with the detection of Cur, providing good selectivity. The constructed sensor was successfully applied to the determination of Cur in drinking water and the food samples with satisfactory results and the RSDs and recoveries were 0.08-5.39% and 95.2-105.2%, respectively. More importantly, the as-prepared NP-Cdots was used as effective fluorescent agent for cellular imaging without noticeable cytotoxicity. The proposed sensor is simple and practical, illustrating that the potential application of NP-Cdots for biosensing, food monitoring and cellular labeling and imaging.