Polyethyleneimine-functionalized carbon dots as a fluorescent probe for doxorubicin hydrochloride by an inner filter effect

A novel fluorescence sensor was designed for the determination of doxorubicin hydrochloride (DOX) based on polyethyleneimine-functionalized carbon dots (PEI-CDs). The PEI-CDs were simply prepared using citric acid as a carbon source and PEI as a modifier based on the “synthesis-modification integration” method. The prepared PEI-CDs exhibited excellent optical properties, and the fluorescence emission was efficiency quenched in the presence of DOX based on inner filter effect (IFE). There was a linear relationship between quenching efficiency and DOX concentration in the range of 0.1–150 μM under the best detection conditions, and the detection limit as low as 75.2 nM. In addition, the new IFE-based sensing platform was successfully used to detect DOX in real samples with satisfactory results obtained.