Wrapping nanocrystals with an amphiphilic polymer preloaded with fixed amounts of fluorophore generates FRET-based nanoprobes with a controlled donor/acceptor ratio.
Colloidal nanocrystal (NC) donors wrapped with a polymer coating including multiple organic acceptor molecules are promising scaffolds for fluorescence resonance energy transfer (FRET)-based nanobiosensors. Over other self-assembling donor-acceptor configurations, our preloaded polymers have the virtue of producing compact assemblies with a fixed donor/acceptor distance. This property, together with the possibility of stoichiometric polymer loading, allowed us to directly address how the FRET efficiency depended on the donor/acceptor. At the population level, nanoprobes based on commercial as well as custom CdSe/ZnS donors displayed the expected dose-dependent rise in transfer efficiency, saturating from about five ATTO dyes/NC. However, for a given acceptor concentration, both the intensity and lifetime of single-pair FRET data revealed a large dispersion of transfer efficiencies, highlighting an important heterogeneity among nominally identical FRET-based nanoprobes. Rigorous quality check during synthesis and shell assembly as well as postsynthesis sorting and purification are required to make hybrid semiconductor-organic nanoprobes a robust and viable alternative to organic or genetically encoded nanobiosensors.
INSERM, U603, Paris F-75006, France.
Aleksey V
AV
Yakovlev
Feng
F
Zhang
Ali
A
Zulqurnain
Abbasi
A
Azhar-Zahoor
Camilla
C
Luccardini
Stéphane
S
Gaillard
Jean-Maurice
JM
Mallet
Patrick
P
Tauc
Jean-Claude
JC
Brochon
Wolfgang J
WJ
Parak
Anne
A
Feltz
Martin
M
Oheim
D003510:Cyclohexanes / Q000737:chemistry; D004058:Diffusion; D004655:Emulsions; D000431:Ethanol / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D006868:Hydrolysis; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D046529:Microscopy, Electron, Transmission / Q000379:methods; D015233:Models, Statistical; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D009821:Oils; D013696:Temperature
D003510:Cyclohexanes; D004655:Emulsions; D008823:Micelles; D009821:Oils; D000431:Ethanol; C506365:Cyclohexane