A Turn-Off Fluorescent Nanosensor for Iron in Aqueous Solution Based on Fluorescent Carbon Nanoparticles

Abstract

The water-soluble°uorescent carbon nanomaterials with low toxicity and high biocompatibility are considered as promising materials for biomedical and sensor applications. Here, we report that a nanosensor system has been developed to simultaneously detect two valence states of iron (Fe 2þ and/or Fe 3þ ) in aqueous solution based on°uorescent carbon nanoparticles (FCNs). The nanosensor has high selectivity and sensitivity with a limit of detection (LOD) of 5 M, which is equivalent to 0.3 mg/L (5.36 M) of iron in drinking water by United States Environment Protection Agency (US-EPA). Furthermore, a distinguishable color change of solution, from pale yellow to red-brown, can be observed as iron concentration reaching 40 M, which provides way for fast, visible detection of irons.