A Mn:ZnSe quantum dot-based turn-on fluorescent sensor for the highly selective and sensitive detection of Cd2+

Abstract

A highly selective and sensitive nanoprobe with fluorescence turn-on sensing properties for recognizing Cd²⁺ was developed through replacing Mn²⁺ near the surface of Mn:ZnSe quantum dots (QDs). The similar ionic radii of Cd²⁺ and Zn²⁺ make the replacement of superficial Zn²⁺ by Cd²⁺ possible, followed by the replacement of external Mn²⁺ by Cd²⁺. Thus, this fluorescence turn-on strategy possesses great selectivity for the determination of Cd²⁺. Based on this strategy, the limit of detection (LOD) for Cd²⁺ is 18 nM, which is superior to the LOD of most reported fluorescent nanomaterial-based probes.