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

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.