PONAME – Développement d’un Nouvel Outil de Nanométrologie Polyscopique Couplant Spectrométrie de Masse et Spectroscopie Laser

Fiche  technique du Projet

• Programme de financement: Programme ANR Retour Post-Doctorants – Edition 2011
• Coordinateur: Université Claude Bernard Lyon 1, Dr. Tristan Doussineau
• Budget Total: € 417.460
• Subvention : € 227.760
• Durée : 01/07/2012-30/06/2014

Context / Contexte

Nanomaterials, nanoparticles and other engineered nanoscale constructs (ENCs) hold great promise for medical, technological and economical benefits. ENCs are anticipated to contribute significantly to the development of new “smart” materials, the next generation of electronics as well as new nanotherapeutics and diagnostics. Although nanotechnology is still considered as a young science there is a rapid expansion of novel ENCs. Knowledge about the toxicity and environmental impact of ENCs is typically missing. It is clear that ENCs toxicity evaluation on animals is strongly impeded due to cost, duration and ethical issues. Prior to any thorough study at the nanobiointerface, an exhaustive
physico-chemical characterization of ENCs is of high relevance since these features can be correlated to their biological and toxicological responses. A wide variety of analytical tools exists in order to investigate the nanometrology of ENCs. All these analytical tools are complementary techniques; however, they suffer from unavoidable inherent limitations facing the extremely wide variety of ENCs in terms of composition and complexity (multifunctional ENCs). There is no single method that can be considered complete and satisfactory, each method providing only a cross-section of the whole information body. In this context, requirements for developing a new nanometrology instrument include flexibility, robustness, accuracy/reliability, multi-parameters measurability, rapid measurement as well as low cost. The PONAME project aims at developing such a new analytical tool coupling mass spectrometry and laser spectroscopy for polyscopic nanometrology.

Objectives / objectifs

The operational objectives of this project include: i) The development of unique experiments  combining ion monitoring and fluorescence measurements. Development of a charge-detection mass spectrometry device in a single ion detection approach. This will allow the highly reliable and accurate determination of mass and charge distributions of polydisperse ENC samples of various natures and compositions. 
•Laser-induced photo-dissociation of single trapped "megadaltonM ion derived ENC samples. This experiment is expected to provide insight on the structure of the trapped ion in relation to its mass and charge as well as incident wavelength of the laser beam.
•Gas phase fluorescence on single trapped ion derived from tailor-made hybrid nanosystems. Intrinsic optical properties of the trapped ion will be measured allowing the rationalization these effects relatively to the core size and shape, the nature of the ligand and the chromophore unit.  ii) The synthesis  of tailor-made  hybrid nanosystems  for the experiments  
•Not only the size and the nature of the NPs will be tuned from small metal cluster to large colloids but also the size and the nature of the organic part will be tuned from dyes or small building blocks of biomolecules to large proteins. 
•The nature of the binding between the organic and the metal parts will be tuned by specific functionalization of the NPs and/or the organic molecules.   The charge-detection mass spectrometry device which allows studying systems in the range of megadalton MW is totally new in France. To our knowledge, the photo-dissociation on single megadalton weighted ion has never been performed so far. The coupling with fluorescence is a first in the world and opens the possibility of doing unique fluorescence experiments on isolated nanoscale systems. The resulting polyscopic analytical device will potentially provide a multi-scale physico-chemical characterization of various ENCs. This ambitious and relevant project in the current context of nanotechnology is expected to have a high and wide impact towards the scientific community through the writing of articles in highly ranked journals. Socio-economic consequences may be expected through the partial or full large-scale commercialization of the resulting device.  Charge monitoring of a single trapped ion through laser-induced photo-dissociation is not trivial to implement. Key issues will be the efficiency of the trapping in terms of duration and the related irradiation time necessary to actually observe changes in charge.  A laser-induced fluorescence experiment is difficult to implement with an ion trap. The detection efficiency for photons is much smaller than for ions, mainly because of the reduced solid angle of collection. Furthermore, the application of this technique to single ion monitoring is challenging.  PONAME project is a multidisciplinary project calling for expertise in nanoparticles preparation and characterization as well as in instrumental development, i.e. coupling lasers to a mass spectrometry device. All these knowledge and skills are gathered and shared between the applicant and the host institution making achievable the goals of this ambitious project.

Impact/ results – Impact/résultats

The PONAME project suggests to develop a unique analytical tool that will provide accurate, fine and rich physico-chemical characterization of sampled megadalton weighted objects or compounds as followed:
- charge detection mass spectrometry (CD-MS) will allow, in a single event approach, the direct determination of a true and accurate mass/size distribution. In addition, study of the mass/charge relationship in these megadalton weigthed objects will be of interest in a fundamental point of view by correlating the maximum charge at a given mass to the Rayleigh limit.
- Laser induced photo-dissociation on single trapped megadalton ion will be carry out. This unique experiment is expected to provide relevant information on the structure, the morphology and/or surface properties of the trapped macroion of selected mass and charge.
- Fluorescence spectroscopy in the gas phase on single trapped macroion will also be performed. We will thus be able to determine the intrinsic optical properties of a megadalton object relatively to its mass/size, charge and structure/morphology. Such a fine analysis might solve partially contradictory results described in the literature on hybrid nanoobjects such as Au@chromophore ranging from full quenching to dramatic increase of the fluorescence.

Rôle de LIP

LIP a accompagné le porteur de projet dans toute la phase de montage et de mise en place de la convention avec l’ANR.