Highly Fe-Selective Fluorescent Nanoprobe Based on Ultrabright N/P Codoped Carbon Dots and Its Application in Biological Samples.

Measuring the levels of Fe in human body has attracted considerable attention for health monitoring as it plays an essential role in many physiological processes. In this work, we reported a selective fluorescent nanoprobe for Fe detection in biological samples based on ultrabright N/P codoped carbon dots. By employing adenosine 5'-triphosphate (ATP) as the carbon, nitrogen, and phosphorus source, the N/P codoped carbon dots could be simply prepared through hydrothermal treatment. The obtained carbon dots exhibited high quantum yields up to 43.2%, as well as excellent photostability, low toxicity, and water solubility. Because of the Fe-O-P bonds formed between Fe and the N/P codoped carbon dots, this nanoprobe showed high selectivity toward Fe against various potential interfering substances in the presence of EDTA. The fluorescence quenching of as-fabricated carbon dots was observed with the increasing Fe concentration, and the calibration curve displayed a wide linear region over the range of 1-150 μM with a detection limit of 0.33 μM. The satisfactory accuracy was further confirmed with the river samples and ferrous sulfate tablets, respectively. With the above outstanding properties, these N/P codoped carbon dots were successfully applied for direct detection of Fe in biological samples including human blood serum and living cells. As compared to the most reported carbon dots-based Fe sensors, this nanoprobe showed high fluorescence, good accuracy, and excellent selectivity, which presents the potential practical application for diagnosis of Fe related disease.