Highly Sensitive and Selective Fluorescence Turn-On Detection of Pb (II) Based on Fe3O4@Au-FITC Nanocomposite

New nanocomposites, Fe3O4@Au-FITC, were prepared and explored to develop a fluorescent detection of Pb2+. The Fe3O4@AuNPs-FITC nanocomposites could be etched by Pb2+ in the presence of Na2S2O3, leading to fluorescence recovery of FITC quenched by Fe3O4@Au nanocomposites. With the increase of Pb2+ concentration, the fluorescence recovery of Fe3O4@AuNPs-FITC increased gradually. Under optimized conditions, a detection limit of 5.2 nmol/L of Pb2+ with a linear range of 0.02-2.0 mu mol/L were obtained. The assay demonstrated negligible response to common metal ions. Recoveries of 98.2-106.4% were obtained when this fluorescent method was applied in detecting Pb2+ spiked in a lake-water sample. The above results demonstrated the high potential of ion-induced nanomaterial etching in developing robust fluorescent assays.

Automated summary

New nanocomposites, Fe3O4@Au-FITC, have been prepared and explored for the fluorescent detection of Pb2+. The method has shown a detection limit of 5.2 nmol/L and a linear range of 0.02-2.0 mu mol/L for Pb2+, with minimal response to common metal ions, and demonstrated successful detection of Pb2+ spiked in a lake-water sample with recoveries of 98.2-106.4%. Through ion-induced nanomaterial etching, this method shows great potential for developing robust fluorescent assays.