Fast and Selective Detection of Cr(III) in Environmental Water Samples Using Phosphovanadate Y(VPO):Eu Fluorescence Nanorods.

Phosphovanadate Y(VPO):Eu nanorods have been created via a simple hydrothermal method and used for the highly sensitive and selective fluorescence detection of Cr over other common heavy metal ions within a 10 min period. It was found that the fluorescence intensity of Y(VPO):Eu linearly decreases with Cr concentrations ranging from 1 × 10 to 1.2 × 10 M. The sensing mechanism for Cr is ascribed to the aggregation of Y(VPO):Eu nanorods triggered by Cr ions owing to the high affinity of phosphate groups to metal ions. The excellent chemical stability, photostability over a wide pH range of 3-12, and high salt-tolerance performance with ionic strength from 1× 10 to 12 M of Y(VPO):Eu allow these nanorods to successfully overcome the photobleaching and pH-dependent fluorescence property of traditional organic fluorescence probes. These characteristics ensure their applicability to environmental monitoring of Cr. The sensitive determination of Cr in different environmental water samples demonstrated the potential application of Y(VPO):Eu as a practical environmental probe. With the help of a UV lamp (254 nm), the visual Cr values for dynamic monitoring in industrial wastewater further verified that this method can even exhibit on-site visible features in daytime and night easily. This allows for the direct monitoring of environmental Cr.