Terbium to Quantum Dot FRET Bioconjugates for Clinical Diagnostics: Influence of Human Plasma on Optical and Assembly Properties

Sensors

Frank Morgner¹  Stefan Stufler¹  Daniel Geißler⁵  Igor L. Medintz²  W. Russ Algar²  Kimihiro Susumu⁴  Michael H. Stewart⁴  Juan B. Blanco-Canosa³  Philip E. Dawson³ 

[1] NanoPolyPhotonik, Fraunhofer Institut für Angewandte Polymerforschung, D-14476 Potsdam, Germany; E-Mails:;Center for Bio/Molecular Science and Engineering, Code 6900, US Naval Research Laboratory, Washington, DC 20375, USA; E-Mails:;Departments of Cell Biology and Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA; E-Mails:;Optical Sciences Division, Code 5611, US Naval Research Laboratory, Washington, DC 20375, USA; E-Mails:;Physikalische Chemie, Universität Potsdam, D-14476 Potsdam, Germany; E-Mail:

关键词: FRET;    quantum dots;    terbium;    luminescence lifetime;    blood;    plasma;    clinical diagnostics;    biotin;    streptavidin;    histidin;    immunoassay;   

DOI  :  10.3390/s111009667

来源: mdpi

【 摘 要 】

Förster resonance energy transfer (FRET) from luminescent terbium complexes (LTC) as donors to semiconductor quantum dots (QDs) as acceptors allows extraordinary large FRET efficiencies due to the long Förster distances afforded. Moreover, time-gated detection permits an efficient suppression of autofluorescent background leading to sub-picomolar detection limits even within multiplexed detection formats. These characteristics make FRET-systems with LTC and QDs excellent candidates for clinical diagnostics. So far, such proofs of principle for highly sensitive multiplexed biosensing have only been performed under optimized buffer conditions and interactions between real-life clinical media such as human serum or plasma and LTC-QD-FRET-systems have not yet been taken into account. Here we present an extensive spectroscopic analysis of absorption, excitation and emission spectra along with the luminescence decay times of both the single components as well as the assembled FRET-systems in TRIS-buffer, TRIS-buffer with 2% bovine serum albumin, and fresh human plasma. Moreover, we evaluated homogeneous LTC-QD FRET assays in QD conjugates assembled with either the well-known, specific biotin-streptavidin biological interaction or, alternatively, the metal-affinity coordination of histidine to zinc. In the case of conjugates assembled with biotin-streptavidin no significant interference with the optical and binding properties occurs whereas the histidine-zinc system appears to be affected by human plasma.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.