title: Luminescent 'On-Off' CdSe/ZnS quantum dot chemodosimeter for hydroxide based on photoinduced electron transfer from a carboxylate moiety.
abstract: A CdSe-ZnS quantum dot (QD) has been surface functionalised by a place exchange reaction with p-mercaptomethyl benzoate synthesized by a three-step procedure. The resulting lumophore-spacer-receptor QD-conjugate was characterized by IR, UV-visible and fluorescence spectroscopy. The emission profile of the QD reveals a narrow emission peak centred at 542 nm. Addition of hydroxide to the solution containing the QD-conjugate results in quenching of the original fluorescence, which is attributed to a photoinduced electron transfer reaction from the electron-rich benzoate moiety to the QD valence band. This is the first reported example of fluorescent quenching of a CdSe-ZnS QD luminescence by an aryl carboxylate moiety.
authors.affiliation: Department of Chemistry, University of Malta, Msida, MSD 2080, Malta.
authors.forename: Lara A
authors.initials: LA
authors.lastname: Gauci
authors.forename: Lindsay G
authors.initials: LG
authors.lastname: Kelland
authors.forename: David C
authors.initials: DC
authors.lastname: Magri