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The nanoparticle-scope : a new integrated instrument for accurate and reproducible physico-chemical characterisation of nanoparticles (npSCOPE)

Periodic Reporting for period 2 - npSCOPE (The nanoparticle-scope : a new integrated instrument for accurate and reproducible physico-chemical characterisation of nanoparticles (npSCOPE))

Reporting period: 2018-01-01 to 2019-06-30

The npSCOPE project aims at developing a new integrated instrument (the nanoparticle-scope) optimised for providing a complete physico-chemical characterisation of nanoparticles both in their pristine form or embedded in complex matrices such as biological tissues. Using sophisticated correlative data processing methodologies and algorithms based on statistical methods in conjunction with appropriate visualisation methods of the results, the npSCOPE instrument will allow rapid, accurate and reproducible measurements.

The instrument will be based on the Gas Field Ion Source as a key enabling technology, which we will combine with a number of new developments in the field of electron and ion microscopy. We will progressively ramp up the TRL of the instrument and associated methodologies to reach TRL 7 by the end of the project. The new technology, and all related processes and methodologies, will be validated via round-robin studies performed independently by several partner institutions, crosschecked with conventional analysis technologies to demonstrate the advancements and capabilities of the npSCOPE technology and benchmarked in representative case studies. Given the low sample quantities needed and the strong potential of the instrument to generate high-quality physico-chemical data on nanomaterials, both ex situ and in situ,
npSCOPE will allow a major step forward in defining key descriptors for read-across, grouping, in silico modelling and creating meaningful relationships with biological activity data for QSAR purposes.

To reach these objectives, the project consortium will be composed of research centres internationally recognised for innovative instrument developments, well-established instrument manufacturers and experts in nanotoxicology in various fields of application to demonstrate and validate the applicability of npSCOPE for the risk assessment of nanomaterials in consumer products.
The npSCOPE project is built around several questions for the characterisation of nanoparticles in (nano-)toxicology, which are classified in three domains:
1. What does the material look like?
2. What is the material made of?
3. What factors affect how a material interacts with its surroundings?

The overarching objective of the npSCOPE project is to develop a single instrument in combination with dedicated methodologies that will answer these three questions in a rapid, accurate and reproducible way, both for nanoparticles in their pristine form and embedded in complex matrices. While a particular focus will be on inorganic nanoparticles, as these account for the most abundant group as outlined above, we will also investigate the potential of npSCOPE on organic nanoparticles using two test cases.

This overarching objective of the npSCOPE project can be differentiated into the following sub-objectives:
1. Development of hardware based on the Gas Field Ion Source (GFIS) as a unique key enabling technology to enable an original in situ real-time combination of Scanning Transmission Helium Ion Microscopy (STIM), Secondary Electron (SE) imaging and Secondary Ion Mass Spectrometry (SIMS) in one single platform. A cryo-stage compatible with the above described characterisation techniques will be part of the final solution. The GFIS can be operated with He+ and Ne+ ion beams and has a high brightness of 4x10^9 A.cm-2.sr-1 with an energy spread of less than 1 eV, enabling very small spot sizes (He+ spot sizes of 3 Å have been demonstrated) while maintaining an ion current that is appropriate for imaging and analytics.
2. Development of protocols for sample preparation and instrument operation, and correlative methodologies and software tools that will allow the automatic and accurate correlation of high sensitivity and high resolution chemical data with morphological information obtained at 0.5 nm resolution.
3. Development of analytical standards, and standardized exposure scenarios as representative test- cases for validation and cross-checking and benchmarking purposes of the npSCOPE instrument and, in general, for analytical nanomaterial characterization technologies.
4. Development of go-to-market strategies for the npSCOPE instrument taking into account performance criteria, cost, easiness to operate, level of automation, intellectual property and freedom to operate aspects.

During the first year of the npSCOPE project, following work has been carried out to achieve the different objectives:
1. For sub-objective 1:
o The design of the npSCOPE instrument has been almost finalised, including both mechanical and electronic components
o The main chamber has been designed to include the different sub-systems
o Selection and optimisation of technical solution for the SIMS focal plane detector
o Selection of a suitable detector and design of an UHV (ultra-high vacuum) compatible vertical transport system for the detector of the STHIM system
o Design of cryo-components for the npSCOPE instrument and of a cryo-suitcase for sample transfer between partners
2. For sub-objective 2:
o Nano-materials to be used for the test- cases and as analytical standards have been collected and distributed to the partners responsible of the basic characterization, together with the respective MSDS.
o Standard protocols for safe handling, storage and disposal of nano-materials have been drafted and distributed to the partners (Deliverable D1.3). General guidelines for the generation of stable solution of the nano-materials have been drafted and distributed to the partners (Deliverable D1.3).
o Software for data interpretation will build upon the open-source solution ImageJ. Existing plugins have been tested on their suitability for the needs of the npSCOPE project and the development of dedicated plugins has been started.
3. For sub-objective 3:
o This activity has not started yet. The beginning is scheduled for end 2018/beginning 2019 accord
Until the end of the project, a new instrument will be developed that couples the extraordinarily high resolution of the recently commercialised helium-ion microscope with sensors for composition (a mass spectrometer) and 3D visualisation (transmitted ion detector) in order to more fully characterise individual nanoparticles and their interaction with their environment (tissue, cells, etc.) and to better understand the risks they might pose to human health or the environment. Software and sample-handling techniques and hardware will be developed to allow high-throughput analysis (for useful statistical descriptions of real-world samples of many nanoparticles), and to facilitate the use of correlative microscopy techniques for a complete understanding of the context of nanoparticles in biological materials. These techniques and protocols will be tested on a suite of well-characterised representative materials and matrices.
Concept of the npSCOPE project