Research

Blue shift of CdSe/ZnS nanocrystal-labels upon DNA-hybridization

Jürgen Riegler^1,3* , Franck Ditengou^2* , Klaus Palme² and Thomas Nann³

¹  Fraunhofer Institute for Interfacial Engineering and Biotechnology, Nobelstrasse 12, 70569 Stuttgart, Germany

²  Institute of Biology II/Botany, Faculty of Biology, Albert-Ludwig University Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany

³  School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK

author email corresponding author email* Contributed equally

Journal of Nanobiotechnology 2008, 6:7doi:10.1186/1477-3155-6-7

Published:	19 May 2008

Abstract

Luminescence color multiplexing is one of the most intriguing benefits, which might occur by using semiconductor Quantum Dots (QDs) as labels for biomolecules. It was found, that the luminescence of QDs can be quenched, and replaced by a luminescence peak at approximately 460 nm on hybridization with certain regions of Arabidopsis thaliana tissue. This effect is site selective, and it is unclear whether it occurs due to an energy transfer process, or due to quenching and scattering of the excitation light. The article describes methods for phase-transfer of differently coloured, hydrophobically ligated QDs, coupling of DNA strands to the QD's surface, and hybridization of the labelled DNA to different cell types of Arabidopsis thaliana. The reason for the luminescence blue-shift was studied systematically, and narrowed down to the above mentioned causes.