Label-free and ultrasensitive fluorescence assay for Fe3+ detection using DNA-Templated Ag nanoclusters

Abstract

Abstract We report for the first time the selective and sensitive detection of Fe3+ by a label-free fluorescent sensor base on AgNCs@C30. AgNCs@C30 was synthesized, and the averaged size is about 3.0\u2009nm, and the maximal excitation and emission wavelengths were 335\u2009nm and 480\u2009nm, respectively. Fe3+ caused a significantly fluorescence quenching of AgNCs@C30, and a novel and label-free nanosensor for detecting Fe3+ was developed with optimum detection of 303.15\u2009K and 2\u2009min. The linear range for Fe3+ detection was 0.1˜12\u2009μM with the corresponding limit of detection (LOD) of 86\u2009nM. Furthermore, the preliminary detection mechanism was discussed in detail, and the fluorescence quenching was deemed to result from AgNCs@C30 aggregation induced with a relatively weak mutual collision between AgNCs@C30 and Fe3+. This strategy detection of Fe3+ will provide a valuable reference for the detection of metal ions by using nanocluster.