A novel biosensor based on single-layer MoS2 nanosheets for detection of Ag+

In this work, we use for the first time single layer MOS2 as the fluorescence quencher to design a detection method for Ag+ with excellent robustness, selectivity and sensitivity. To maintain the ultrathin MOS2, bulk MOS2 materials have been exfoliated by intercalation with lithium followed by reaction with water. As-prepared two-dimensional MOS2 not only has good water-solubility but also obtains high fluorescence quenching efficiency within 5 min. Importantly, the detection limit of this assay for Ag+ (1 nM) was lower than the maximum limitation guided by the United States Environmental Protection Agency (EPA) and the World Health Organization (WHO). Further, this new Ag+ probe was demonstrated in monitoring Ag+ in lake water samples with satisfactory results. (C) 2014 Elsevier B.V. All rights reserved.