The intensity of emitted light from CdSe quantum dots (QDs)–H2O2is described as a novel chemiluminescence (CL) reaction for determination of dysprosium. This reaction is based on the catalytic effect of Dy
3+
ions, causing a significant increase in the light emission, as a result of the reaction of quantum dots (QDs)
with hydrogen peroxide. In the optimum conditions, this method was satisfactorily described by linear
calibration curve in the range of 8.310
7
–5.010
6
M, the detection limit of 6.010
8
M, and the relative standard deviation for five determinations of 2.510
6
MDy3+
3.2%. The main experimental
advantage of the proposed method is its selective to Dy
3+
ions compared with common coexisting cations, therefore, it was successfully applied for the determination of dysprosium ions in water samples
