Functionalized ME-capped CdSe quantum dots based luminescence probe for detection of Ba2+ ions

Water soluble CdSe quantum dots (QDs) have been synthesized using 2-mercaptoethanol (ME) as surface passivation through one step process by using safe and low cost materials at low temperatures 75 °C. CdSe QDs evaluated as a luminescence probe for barium ions in aqueous solution. Experiment results showed that the fluorescence emission from CdSe QDs was enhanced significantly by barium ions, while other metal ions exhibited no significant effect on QDs. Under the optimal conditions, the response was linearly proportional to the concentration of barium ions ranging from 1.0 × 10−7 to 1.2 × 10−6 mol L−1 with detection limit 4.2 × 10−9 mol L−1. Based on the distinct optical properties of ME-capped CdSe QDs with the barium ions, the high sensitivity, wide linear range and rapid response to metal ions, CdSe QDs can be developed as a potential identified luminescence probe for detection of barium ions in aqueous solution without interference from other foreign metal ions.