Journal of Fluorescence

, Volume 18, Issue 6, pp 1157–1161

Luminescent Detection of ATP in Aqueous Solution Using Positively Charged CdSe–ZnS Quantum Dots

  • John F. Callan
  • Ray C. Mulrooney
  • Sukanta Kamila
Original Paper

DOI: 10.1007/s10895-008-0367-5

Cite this article as:
Callan, J.F., Mulrooney, R.C. & Kamila, S. J Fluoresc (2008) 18: 1157. doi:10.1007/s10895-008-0367-5

Abstract

Commercially available CdSe–ZnS Quantum Dots (QDs) have been modified by exchanging the hydrophobic surface ligands with (2-mercaptoethyl)-trimethylammonium chloride. The resulting water soluble conjugate was titrated with solutions of adenosine triphosphate (ATP), adenosine diphosphate, adenosine monophosphate, guanosine triphosphate (GTP), guanosine diphosphate and guanosine monophosphate in 0.01 M 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid buffer (pH 7.4). A strong fluorescence quench of about 80% was observed for ATP, a quench of 25% was observed for GTP while the others had virtually no effect. The quenching effect of ATP and GTP was attributed to the high negative charge density associated with these substrate’s resulting in a strong attraction to the QD surface enabling them to engage in electron transfer with the excited QD. The lack of fluorescence quenching associated with the other nucleotides was most likely due to their reduced charge density resulting in a lower affinity for the QD surface.

Keywords

Quantum dots Fluorescence ATP Nucleotides 

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • John F. Callan
    • 1
  • Ray C. Mulrooney
    • 1
  • Sukanta Kamila
    • 1
  1. 1.School of PharmacyThe Robert Gordon UniversityAberdeenUK

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