pH-sensitive quantum dots

Massimiliano Tomasulo, Ibrahim Yildiz, Francisco Raymo

Research output: Contribution to journalArticle

152 Citations (Scopus)

Abstract

We have designed organic ligands able to adsorb on the surface of CdSe-ZnS core-shell quantum dots and switch the luminescence of the inorganic nanoparticles in response to hydroxide anions. These compounds incorporate a [1,3]oxazine ring within their molecular skeleton, which reacts with the nucleophilic hydroxide anion to generate a 4-nitrophenylazophenolate chromophore. The chromogenic transformation activates an energy transfer pathway from the quantum dot to the adsorbed chromophores. As a result, the luminescence intensity of the coated nanoparticles decreases significantly in the presence of hydroxide anions. In fact, this mechanism can be exploited to probe the pH of aqueous solutions. Indeed, an increase in pH from 7.1 to 8.5 translates into a 35% decrease in the luminescence intensity of the sensitive quantum dots. Thus, our operating principles for luminescence switching can efficiently transduce a chemical stimulation into a change in the emissive response of semiconductor nanoparticles. In principle, this protocol can be extended from hydroxide anions to other target analytes with appropriate adjustments in the molecular design of the chromogenic ligands. It follows that luminescent chemosensors, based on the unique photophysical properties of semiconductor quantum dots, can eventually evolve from our design logic and choice of materials.

Original languageEnglish
Pages (from-to)3853-3855
Number of pages3
JournalJournal of Physical Chemistry B
Volume110
Issue number9
DOIs
StatePublished - Mar 9 2006

Fingerprint

Semiconductor quantum dots
hydroxides
Anions
Luminescence
Negative ions
quantum dots
Chromogenics
luminescence
anions
Chromophores
Nanoparticles
nanoparticles
chromophores
logic design
Oxazines
Ligands
Logic design
ligands
stimulation
musculoskeletal system

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

pH-sensitive quantum dots. / Tomasulo, Massimiliano; Yildiz, Ibrahim; Raymo, Francisco.

In: Journal of Physical Chemistry B, Vol. 110, No. 9, 09.03.2006, p. 3853-3855.

Research output: Contribution to journalArticle

Tomasulo, M, Yildiz, I & Raymo, F 2006, 'pH-sensitive quantum dots', Journal of Physical Chemistry B, vol. 110, no. 9, pp. 3853-3855. https://doi.org/10.1021/jp060185h
Tomasulo, Massimiliano ; Yildiz, Ibrahim ; Raymo, Francisco. / pH-sensitive quantum dots. In: Journal of Physical Chemistry B. 2006 ; Vol. 110, No. 9. pp. 3853-3855.
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