Photophysics of (CdSe)ZnS colloidal quantum dots in an aqueous environment stabilized with amino acids and genetically-modified proteins

Xin Ai, Qi Xu, Marcus Jones, Qing Song, Shi You Ding, Randy J. Ellingson, Mike Himmel, Garry Rumbles

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21 Citations (Scopus)


Using a combination of two amino acids, histidine and N-acetyl-cysteine, to replace the original organic capping groups of (CdSe)ZnS quantum dots, water-soluble and highly luminescent (CdSe)ZnS quantum dots have been successfully prepared at pH 8. Characterization by steady-state and time-resolved photoluminescence spectroscopy, and transient absorption spectroscopy, demonstrate that the electronic properties of these quantum dots exceed those of the original as-synthesized samples dissolved in a more-conventional organic solvent. Furthermore, these amino acid-stabilized quantum dots have been assembled onto a cellulose substrate via cellulose binding proteins that specifically bind to cellulose and was genetically engineered to harbor dual hexahistidine tags at the N- and C-termini to confer binding with the zinc(ii) on the quantum dot surface. The spectroscopic measurements show that the protein-bound quantum dots continue to retain their desirable electronic properties when bound on the substrate. Meanwhile, the specific and very selective binding properties of the proteins have remained effective.

Original languageEnglish
Pages (from-to)1027-1033
Number of pages7
JournalPhotochemical and Photobiological Sciences
Issue number9
Publication statusPublished - Aug 30 2007


ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

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