Surface-modified CdSe quantum dots for the sensitive and selective determination of Cu(II) in aqueous solutions by luminescent measurements Original Research Article

The use of water-soluble luminescent CdSe quantum dots (QDs), whose surface was modified either with 2-mercaptoethane sulphonic acid or with 2-mercaptoacetic acid, was investigated for the sensitive and selective determination of copper(II) ions in aqueous solutions. A pH 5.5 was selected for measurement. Also, the effect of the presence of different surfactant agents in the sample solution, in order to stabilize the fluorescent signals of the QDs in water, has been investigated. A 10−3 M of dodecyltrimethylammonium chloride final concentration was selected. Fluorescence signals were found to be stable for at least several days in such conditions.