Tunable electrochemiluminescence of CdSe@ZnSe quantum dots by adjusting ZnSe shell thickness

• CdSe@ZnSe QDs via a facile and eco-friendly strategy have been synthesized in aqueous solution for the first time.
• Enhanced electrochemiluminescence of CdSe@ZnSe QDs was observed.
• The electrochemiluminescence of CdSe@ZnSe QDs can be controllable by adjusting the thickness of ZnSe shells.
• The high ECL intensity of CdSe@ZnSe QDs allows colorimetric detection of dopamine using common mobile phone imaging.

CdSe quantum dots as cores capped with ZnSe shell (CdSe@ZnSe QDs) via a facile and eco-friendly strategy have been synthesized in aqueous solution for the first time. The electrochemiluminescence (ECL) of CdSe@ZnSe QDs was greatly enhanced compared to that of CdSe QDs. In particular, the ECL properties of the resulting CdSe@ZnSe QDs were found to be controllable by adjusting the thickness of ZnSe shells. Benefiting from the enhanced ECL intensity, the sensor based on CdSe@ZnSe QDs could accurately quantify dopamine from 10.0 nM to 3.0 μM with a detection limit of 3.6 nM.