Preparation of a Novel Green Fluorescent Carbon Quantum Dots and Application in Fe3+-Specific Detection in Biological System

Trace ferric ion (Fe 3+ ) detection has attracted increasing attention as an essential and indispensable role in many physiological and pathological research. The green-emitting carbon quantum dots (Green-CQDs) were obtained through a green and facile one-step hydrothermal method for the specific recognition and trace detection of Fe 3+ in this paper. The optimal excitation and emission wavelengths of the CQDs were 395 nm and 490 nm, respectively. The stokes shift was up to 95 nm, which can effectively reduce the background fluorescence interference. In addition, it also exhibited good water solubility, stability, and high biocompatibility. The fluorescence intensity of Green-CQDs was linearly related to the concentration of Fe 3+ (range of 0–80 μmol/L), and the detection limit was as low as 59 nmol/L. These good properties were favorable and successful for Fe 3+ detection in tap water, human serum samples and living cells. In addition, a fluorescence visual test paper (FP@CQDs) was prepared utilizing filter paper as carrier, which can quickly identify Fe 3+ in real time, and is suitable for the visualization analysis of Fe 3+ in environment. As an efficient nanoprobe, the Green-CQDs held great promise and bright prospects in practical application in prevention and early clinical diagnosis of Fe 3+ -associated diseases.