Distance-Dependent Fluorescence Quenching on Gold Nanoparticles Ensheathed with Layer-by-Layer Assembled Polyelectrolytes

Université de Rennes 1, Roazhon, Brittany, France
Nano Letters (Impact Factor: 13.59). 04/2006; 6(3):530-6. DOI: 10.1021/nl052441s
Source: PubMed


We report on the preparation, characterization, and photophysical study of new fluorescent core/shell nanoparticles fabricated by electrostatic layer-by-layer assembly. On the basis of gold cores with a diameter of 13 nm, these nanocolloids possess different fluorescently labeled polymer corona layers at various distances from the surface of the core metal using nonfluorescent polyelectrolytes as spacer layers. UV-visible spectroscopy and transmission electron microscopy confirm that the particle suspensions of fluorescently labeled core/shell nanoparticles are stable at all stages of their construction. Photophysical investigations reveal strongly distance-dependent fluorescence quenching in these particle systems. The contribution of the metal core to this quenching can be assesed precisely after the gentle dissolution of the gold cores by potassium cyanide. The photophysical measurements reveal clearly that the gold nanoparticles decrease the transition probability for radiative transitions.

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Available from: M. Blanchard-Desce, Jul 02, 2014
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    • "It is known that the presence of metallic nanostructures in close proximity to quantum dots can modify their photoluminescence properties [43] [44]. The number of polyelectrolyte layers was chosen to avoid the quenching of the Qdot s 605 nanoparticles since every layer has been reported to have a thickness between 0.5 and 2 nm [45] [46]. Qdot s 605 nanoparticles were functionalized with the polymer poly(isobutylene-alt-maleic anhydride) as reported elsewhere [47] and therefore they were negatively charged (the ζ-potential and hydrodynamic diameter measured in Milli-Q water were À 35.370.6 mV and 1972 nm, respectively). "
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    • "Polyelectolytes (PE) are charged polymers, either positively or negatively charged, which have been extensively used to provide various functionality on surfaces, such as the immobilization of antibodies or other biological probes [1] [2], chemical probes [3] [4], as spacers [5], or as a pH probe [6]. While other surface functionalization processes such as silanization or the deposition of self-assembled monolayer require a specific pretreatment of the surface, PE deposition distinguish itself by alleviating the need to process the surface which is some cases is either impossible or detrimental to the sensor. "
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