Employee Spotlight: Kate McHardy – Head of Sales

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Ionoptika is very proud of its skilled and dedicated staff, who together with our loyal users make up our global community. Our new regular post will shine the spotlight on some of the people who make up Ionoptika!

Kate McHardy - Head of Sales

This week’s spotlight focuses on Ionoptika’s Head of Sales, Kate McHardy. Kate joined Ionoptika in 2019, so is still a relative newcomer to the team. We asked her what she makes of life at Ionoptika so far!

How long have you worked at Ionoptika and what career path brought you to us?

I joined Ionoptika in April 2019, having spent the previous 17 years working in a similar role at a company called Oxford Cryosystems, specialising in cooling devices and cryostats, mainly for X-ray crystallography applications. Like Ionoptika, Oxford Cryosystems was a small yet specialist research and engineering company.  I loved my time there and still have many friends at the company, but after 17 years, felt it was time for a change!

What do you enjoy most about working at Ionoptika?

One of the most exciting things about Ionoptika for me is the important applications that our instruments can be used for. Our J105 SIMS, for example, has been used as a research tool for understanding skin cancer and breast cancer; or demonstrating the presence of cocaine metabolites in fingerprints. It is quite inspiring to meet the researchers working in such important areas, and to feel that the instruments we develop and offer can add such value to these important fields.

I have been involved in international sales and marketing for many years now, and one of my favourite parts of the role is getting out to see customers at their labs to appreciate the work they are doing and attending conferences and exhibitions. So this year, the restrictions on international travel have been rather frustrating!

We have a very talented team at Ionoptika, working on some really diverse R&D projects, so there is no shortage of work for the Sales & Marketing team, as we work out how to commercialise these new developments.

What would a typical day look like for you working in Sales?

In any other year, our Sales & Marketing team attend a lot of conferences and exhibitions. So a typical day might involve preparing for those coming up, attending the meetings, both as a delegate and exhibitor, meeting existing and potential new customers, or following up on discussions we have previously had. This year, this has been replaced with a lot of planning for the future and Zoom meetings!

However, one of the great things about working for Ionoptika, is that no day is the same; and this year, working from home, that’s saying a lot! We have a very talented team at Ionoptika, working on some really diverse R&D projects, so there is no shortage of work for the Sales & Marketing team, as we work out how to commercialise these new developments.

What has been your best memory or achievement in your time at Ionoptika?

In the 18 months of my time with Ionoptika, unfortunately half of that time has been during the Covid-19 pandemic! However my first 9 months with the company was extremely busy and I was lucky enough to attend the SIMS 22 conference in Kyoto, which really allowed me to meet a lot of our customers and collaborators.

What do you enjoy doing in your spare time?

I have only lived on the South Coast for 18 months now, so I am really enjoying getting out walking and exploring the beautiful local area. I do have a passion for travel, but this year, that has necessarily had to be a bit closer to home!

Have you been doing anything interesting/different/new to cope with the lockdown?

Lots of gardening during the summer and lots of walking now!

What are you looking forward to most once the lockdown is over?

At the moment, our region’s restrictions mean we can’t meet other households, so I am most looking forward to meeting up with friends again and being a bit more social. And overseas travel of course, I certainly miss that!

Interested in becoming part of our team? Visit our Careers page.

Analyse v2.0.2.15 Release

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We are happy to announce the release of Analyse v2.0.2.15 for all J105 SIMS customers. This long awaited release brings with it a host of new features as well as several bug fixes. Chief among the new features is a new imzML file converter. To download the new release, simply go to our downloads page and click on the link.

GavynIonoptika 2020

Employee Spotlight: Gavyn Trowbridge

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Ionoptika is very proud of its skilled and dedicated staff, who together with our loyal users make up our global community. In our ongoing series, we shine the spotlight on one of our talented colleagues each month to introduce you to some of the people behind Ionoptika.

This month we move away from new hires to what will be a very familiar face to many of our customers around the world, Senior Test & Service Engineer, Gavyn Trowbridge. Gavyn is one of Ionoptika’s longest serving employees, joining the company in 2004, and today he manages our customer installations and service work around the world. We asked Gavyn for an insight into his time at Ionoptika.

"...knowing that the whole team has had a part to play in the completion of the project, and knowing I am inserting the final piece of the puzzle, whilst installing it, brings a certain joy that can't be explained" - Gavyn Trowbridge, Senior Test & Service Engineer

How long have you worked at Ionoptika and what career path brought you to us?

I joined Ionoptika in Feb 2004, having previously worked in various roles in the manufacturing sector including a PCB factory, high power micro generators, up to 100kW of power from gas turbines. I self-educated through night school and day release. The role at Ionoptika suited me because I have always been interested in taking things apart, seeing how they work, and putting them back together.

What do you enjoy most about working at Ionoptika?

I appreciate the diverse range of skills and experience we have in the factory team, and the toys are pretty cool too. We get paid to play with toys!!

But the prospect that we may be creating something that could change the world for the better is a real buzz; a pharmaceutical breakthrough? A medical research breakthrough? New things never seen before in the field?

You never know what research, or researchers you may meet in the field on a customer site. The projects that our customers work on are each fascinating in their own way!

My favourite part of the role is the final installation of the instruments: knowing that the whole team has had a part to play in the completion of the project, and knowing I am inserting the final piece of the puzzle, whilst installing it, brings a certain joy that can’t be explained.

Can you describe a typical day working at Ionoptika (normally, not in the lockdown!)

There’s never a dull moment in my day and no such thing as a typical day. One day I may be building a prototype, another fixing something, and another testing a customer system. Or just general helping of others with my long-term experience?  I also usually spend quite a lot of time on customer sites around the world.

What has been your best memory or achievement during your time at Ionoptika?

The installation of the J105 instruments is quite exciting. You never know where one might be going and it’s a real buzz to travel to global customer sites to install these systems.

What do you enjoy doing in your spare time?

Gaming, music, walking, meditation, the great outdoors. Often meditating in places of beauty.

Have you been doing anything interesting/different/new to cope with the lockdown?

Trying to stay sane!!! Making the most of not being away and making home improvements.

What are you looking forward to most once the lockdown is over?

Enjoying the great outdoors more, exploring new places. This year’s holiday was going to be an eastern European adventure, taking in 4 countries, but this is now postponed until next year!

Interested in becoming part of our team? Visit our Careers page.

GCIB SEM GCIB 10S gas cluster ion beamIonoptika 2020

GCIB-SEM: 3D electron microscopy with < 10nm isotropic resolution

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GCIB-SEM is a new technique that combines high resolution electron microscopy with the damage free sputtering of gas cluster ions to produce incredible 3D tomography with less than 10 nm isotropic resolution.

Over the last two decades, gas cluster ion beams (GCIB) have become increasingly popular as add-on components for ultra-high vacuum techniques such as XPS, SPM, and SIMS. Due to their excellent combination of fast yet low-damage sputtering, GCIBs have been widely adopted as depth profiling ion beams, or as a means of cleaning samples in situ.

Very low impact energies, as little as 1 eV per atom, means cluster ions sputter material without modifying the surface chemistry, i.e. without breaking bonds. This makes GCIBs particularly effective for high-resolution depth profiling of soft materials such as polymers and organic matter.

GCIB 10S cluster schematic, and PET C 1s XPS spectrum comparing Ar1 and Ar2000.
The GCIB 10S is a powerful tool for damage-free depth profiling of polymers, organics, and other soft materials, delivering consistently superior results over monatomic beams.

Traditional sputter beams such as Ar1 typically have impact energies in the kilovolt range, resulting in not only large amounts of fragmentation to surface molecules, but also penetration of the ions beneath the surface causing further damage. This damage shows up in XPS and SIMS spectra, and limits the depth resolution of the technique.

Cluster beams also sputter soft, organic material much faster than hard, inorganic materials, making them extremely useful for removing adventitious carbon and other surface contamination without damaging the substrate — ideal for cleaning surfaces prior to analysis.

It is no surprise then that GCIBs have become so popular as add-on components for surface analysis instrumentation.

The GCIB 10S

  • 10 kV argon cluster ion source
  • Selectable clusters from Ar1 to > Ar3000
  • Real-time cluster measurement & adjustment
  • Sample current imaging
  • Gate valve for quick & easy servicing
  • Large spot size and wide scan field for even removal of material

The versatile nature of the GCIB makes it a useful tool in a variety of other techniques as well, beyond strictly surface science. In particular, the GCIB has recently been shown to be powerful tool in electron microscopy. A new technique pioneered by researchers at HHMI Janelia Research Campus combines high resolution electron microscopy with the damage free sputtering of gas cluster ions to produce incredible 3D tomography with less than 10 nm isotropic resolution.

Published in Nature Methods in 2019 the GCIB-SEM system developed by Hayworth et al. consists of a GCIB 10S from Ionoptika mounted on a Zeiss Ultra SEM. Using 1 µm thick serial sections of brain tissue, high-resolution electron imaging was interleaved with wide-area ion milling until the entire section was consumed. Full experimental details can be found in the paper linked above.

Figure detailing results achieved using GCIB SEM, by Hayworth et al
GCIB-SEM is a powerful technique for acquiring extremely detailed 3D maps on an unprecedented scale. Images from a GCIB-SEM run performed on three sequential 500-nm-thick sections of mouse cortex. bioRxiv: http://dx.doi.org/10.1101/563239.

The result is a 3D data set hundreds of microns in area by tens of microns deep, with less than 10 nm isotropic resolution throughout. Such a high resolution data set then allows researchers to map the brain structure in incredible detail. The figure above shows a 15 x 15 x 10 µm section of mouse brain, the detail of which is truly remarkable. Panel e shows a single spiney dentritic process with axons synapsing on it, while panel f shows various high-resolution 2D and 3D views of a single spiney synapse.

Other technologies used to perform similar experiments include FIB-SEM and diamond knife based sectioning, however both have their drawbacks. FIB provides the necessary resolution, but is thus far incompatible with the high-throughput needed for larger volumes, while diamond knife techniques are highly compatible with larger volumes, but lack the consistency needed at such thin cuts.

In contrast, the GCIB 10S mills away just the top few nanometres of the surface resulting in an improvement in depth resolution of a factor of 3 or more over other techniques, whilst simultaneously improving sectioning reliability. The rapid, wide area milling afforded by the GCIB 10S is also compatible with the new multi-beam SEM systems now on the market, which will enable even larger volumes to be analysed with no loss of resolution.

GCIB-SEM

  • Large-area and fast (up to 450 µm3 s-1).
  • Can be automated and is highly scalable.
  • Consistent performance over large volumes.
  • Simple, easy to maintain, and reliable.
  • Improves z resolution by a factor of 3 or more.

GCIB-SEM is a powerful technique for exploring complex materials and structures in three dimensions with extraordinary detail. For this application, control of the cluster size and current is critical to the result. Unlike other gas cluster beams, the GCIB 10S lets the user take complete control of the experiment. With real-time cluster measurement, cluster size can be tuned to the users’ needs and the settings saved for later use.

Real-time cluster measurement on the GCIB 10S

The GCIB 10S is easily installed on a range of instrumentation, from XPS and SIMS, to electron microscopes, Auger, and more. To speak with us and find out how the GCIB 10S might be right for your application, or to request a brochure, please get in touch via our Contact Page.

C60 moleculeIonoptika 2020

Why you shouldn’t overlook C60 beams just yet

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C60 cluster ion beams are a fantastic tool for analyzing both hard and soft materials. Composed of sixty carbon atoms arranged into a football shape, C60 ions combine several different features making it a great all-rounder ion beam. This is why we always recommend customers to consider including a C60 beam when specifying their J105.

As the C60 molecule is larger (approx. 7 Å) than the lattice constant for most materials, it does not experience channeling the way smaller ions such as bismuth do. As such C60 beams exhibit incredibly uniform sputter rates across a wide range of materials, and even on challenging poly-crystalline materials where there is a range of crystal orientations.

As a cluster ion, C60 also produces very shallow craters with very little, if any, subsurface damage, so etch cycles are not needed to remove damaged layers when performing depth profiles or 3D imaging. As the J105 samples 100% of the analysis volume, high sensitivity is guaranteed, and combined with spot sizes as low as 300 nm, C60 is a powerful beam for delivering maximum resolution in 2D and 3D.

NiCr Standard Depth Profile C60
C60 depth profile through the NIST NiCr standard showing <5 nm depth resolution. As there is no need to perform etch cycles to remove damaged layers, depth resolution on the J105 is limited only by the crater depth of the ion beam.

The figure below shows a 3D image of a semiconductor stack alongside a depth profile through the same, performed with a 40kV C60 beam in positive ion mode. The sample consists of layers of InSb, Al, and GaAs respectively, covered in a protective photoresist layer.

3D SIMS image of InSbAlGaAs Stack with depth profil
The J105 has one mode of operation, so amazing 3D images, high-resolution 2D images, as well as detailed depth profiles can all be obtained from a single data set.

The resulting 3D SIMS image shows the layers in amazing clarity, with very sharp interfaces. As the J105 always samples 100% of the analysis volume, high sensitivity is guaranteed. The detailed depth profile through the sample also shows the presence of dissolved Al within the InSb layer, as well as the presence of Sb in the pure Al layer.

The 40kV C60 beam is ideal for this type of sample or application due to the combination of soft organic, inorganic, and hard metallic layers within the same sample. Combined with spot sizes as low as 300 nm, C60 is a powerful beam for delivering maximum resolution in 2D and 3D, no matter what type of sample you have.

gcib 10s webinarIonoptika 2020

GCIB 10S Webinar in association with UCVAC

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On Thursday, in collaboration with UCVAC, we held a webinar on the GCIB 10S Gas Cluster Ion Beam for potential customers in China. The webinar was a great success, and we will certainly look to use this format again to connect with potential customers around the world, particularly while travel restrictions remain in place.

IONOPTIKA recently authorized UCVAC as its sole agent in mainland China and Hong Kong. With extensive experience in the surface science markets, UCVAC are well placed to assist business development and provide technical support in the region. We look forward to working together, and this webinar was a fantastic way to kick things off.

The GCIB 10S is a high-performance gas cluster ion beam that delivers rapid, low-damage sputtering for superior quality surface analysis. An ideal upgrade for a variety of instruments, such as XPS, SEM, SPM, and SIMS, the GCIB 10S brings many powerful advantages in an economical, low-maintenance package.

Ultra-low-energy sputtering by argon cluster ions helps to efficiently remove material while producing very low damage and minimal loss of chemical information, leaving a pristine surface for analysis. Removing just a few nanometres per cycle, the GCIB 10S is the ideal tool for achieving ultra-high-resolution depth profile analysis.

If you missed it live, you can watch the full webinar below.

Employee Spotlight: Dr Michal Ryszka

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As a small company, Ionoptika is very proud of its skilled and dedicated staff, who together with our loyal users make up our global community. So each month we will be putting the spotlight on one of our talented colleagues to introduce you to some of the people behind Ionoptika.

This month, continuing the theme of new hires, we introduce Dr. Michal Ryszka, who joined Ionoptika in 2019. Michal gained his experience during postdocs in both France and the USA before joining Ionoptika as Development Engineer with special responsibility for Ionoptika’s J105 SIMS instrument.

We asked Michal for some insight into the pivotal points in his career:

Michal quotation

Why did you decide to study science when you were at school or university?

I was always interested in how things work, both in terms of science and technology, so when I was in high school and it came down to choosing what I want to study at University it was really an easy choice. I went for applied physics at Gdansk University of Technology. I got interested in atomic and molecular physics, so after getting a degree in science and engineering I went for a PhD at the Open University in the UK in Chemical Physics.

What do you enjoy most about working at Ionoptika?

One of the most exciting parts of my job is being involved in the development of a cutting-edge technology.  Knowing how many applications benefit from our products is really motivating!

Can you describe a typical day working at Ionoptika (normally, not during the lockdown!)

I spend most of my time running ion simulations and analysing results for a future development project. I am also involved in development projects run by other colleagues. I can be also found with my hands on the J’s currently being built, tweaking and tuning.

What has been your best memory or achievement in your career?

My best memory is of the day when I finally recorded first hydrated DNA base cluster ions in an experimental setup I had been developing for my PhD project.

What do you enjoy doing in your spare time?

Whenever the weather allows it, I like mounting biking. I also like reading books and playing video games.

Have you been doing anything interesting/different/new to cope with the lockdown?

I am trying to stay fit by riding on my turbo trainer. I have also been doing lots of research for a project I am looking forward to after the lockdown is over.

What are you looking forward to most once the lockdown is over?

I’m planning to buy a van and turn it into a campervan, then take it for mountain biking trips around the UK and the continent.

You can catch up with Michal and the rest of the Ionoptika team at various conferences throughout the year. Interested in becoming part of our team? Visit our Careers page.

Drug detection with high-sensitivity using ToF SIMS

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The high attrition rate of pharmaceutical drug compounds adds enormously to the cost of those that make it to market, so there is an urgent and growing need to identify failure at earlier stages of drug development.

In order to do so, researchers require as much information as possible. Specifically, there is a need to measure the concentration of a drug at the target in order to accurately predict its pharmacological effect. This then requires a means of generating label-free sub-cellular imaging, as fluorescent labels may affect drug chemistry, altering results.

Time of flight secondary ion mass spectrometry (ToF SIMS) is a powerful tool for label-free chemical imaging, having typically very high lateral resolution capable of resolving sub-cellular features with 3D analysis capabilities.

ToF SIMS is thus a potentially powerful analysis tool for the screening of new drug compounds. However, the use of high energy projectiles for ToF SIMS analysis can cause molecules to fragment, preventing the molecular ion from being detected. This can lead to a lot of ambiguity, for example distinguishing between a drug compound and its metabolites.

Another possible stumbling block is the issue of sensitivity, particularly for those compounds of most interest. In a recent study by the National Physical Laboratory (NPL), Vorng et al. demonstrate that the sensitivity in ToF SIMS is proportional to the Log P of that compound, such that compounds with low or negative Log P values are extremely difficult to detect.  

Log P, or partition coefficient, is a measure of hydrophobicity, and is a major factor used in pre-clinical assessment of a compound’s druglikeness.  It is advisable that a drug candidate be as hydrophilic as possible while still retaining adequate binding affinity to the therapeutic protein target, i.e. that the Log P be as low (or negative) as practicable. This presents an obvious problem for the use of ToF SIMS as an analytical tool in this context.

Cluster beam colliding with a surface.

We have recently led the development of a new type of ion source for ToF SIMS that provides unparalleled sensitivity particularly for organic species. Available exclusively on the J105 SIMS, the Water Cluster Source simultaneously reduces fragmentation while increasing ionization, for truly unparalleled sensitivity of drugs, metabolites, biomarkers, lipids, peptides and more.

Combining this new ion source with the already impressive sensitivity of the J105 SIMS, even low Log P compounds can be detected in tissue and cells, with direct, label-free imaging of the molecular compounds at sub-cellular resolutions.

To demonstrate this, we doped tissue homogenate with 4 different pharmaceutical compounds that span the range of Log P from -0.8 to 7.6. The relationship between sensitivity and Log P reported by NPL is observed in this data, however the slope of the line is greatly reduced, with only a factor of 40 between the highest and lowest values.

ToF SIMS sensitivity to drugs as a function of Log P
ToF SIMS sensitivity of four different drugs using the Water Source. Sensitivity shows a linear relationship to the partition coefficient, Log P, though the slope is not steep.

As a comparison, we performed the same experiments with a state-of-the-art Ar gas cluster ion beam and plotted the yield against that of the new Water Source. The Water Source increased sensitivity by an order of magnitude in most cases, with the largest increase being for those compounds with the lowest Log P values. This indicates that the improvement in sensitivity is greatest for those compounds that need it the most.

Comparing sensitivity of argon and water cluster beams for four different drugs
Comparing sensitivity of a state-of-the-art Ar cluster source with the Water Source. Sensitivity improves by roughly an order of magnitude when using water, with the largest increase for those compounds with lower Log P values.

As a final demonstration of the capabilities of the J105 with the Water Source, we performed tandem MS analysis on the homogenate samples. Tandem MS is an important step for confirming any assignment in mass spectrometry, however the inefficiency of the process often means it can only be performed on high intensity peaks. With the boost in sensitivity provided by the Water Source, tandem MS analysis is possible even on compounds with relatively low Log P values, such as ciprofloxacin.

Tandem MS analysis of the drug ciprofloxacin
Tandem MS performed on the J105 SIMS with a Water Source. Greater sensitivity allows definitive confirmation of many more peaks.

ToF SIMS is a potentially powerful analysis tool for the screening of new drug compounds, however research is hampered by the inherently low sensitivity to many drug candidates. The J105 SIMS in combination with the Water Cluster Source provides unparalleled sensitivity to drug compounds, particularly in complex matrices such as tissue and cells, even for low Log P compounds. This unprecedented sensitivity combined with sub-cellular imaging and high-resolution 3D imaging mean the J105 SIMS is a powerful tool for drug analysis.

To learn more about how the J105 SIMS can benefit your research or to set up a demonstration, get in touch via our Contact Page.

Employee Spotlight: Dr Naoko Sano

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As a small company, Ionoptika is very proud of its skilled and dedicated staff, who together with our loyal users make up our global community. So each month we will be putting the spotlight on one of our talented colleagues to introduce you to some of the people behind Ionoptika.

The first to be in the spotlight is one of most recent hires, Dr Naoko Sano, our new Applications Scientist. We asked Naoko about her career and what she enjoys about working at Ionoptika.

Employee spotlight - quote

Where were you before you started at Ionoptika?

I joined Ionoptika from Nara Women’s University in Japan where I was Associate Professor in textile science.

What does a typical day look like for you?

Most days I spend my time working on new applications and processing SIMS data. At lunch time I sometimes like to go for a walk with friends from the office, which really helps me refresh. The rest of the time I can be found running samples on the J105 ToF SIMS instrument for existing and potential customers. I’m also involved in testing new software and providing feedback back to the software team.

What do you love most about your job?

One of the most exciting parts of my job is the great variety of applications that I’m involved in, from investigating neurotransmitters in brain tissue, to analysing the frictional properties of lubricants. This makes the job of Application Scientist immensely challenging but hugely rewarding!

Why did you decide to study science when you were at school or university?

A working experience with the Surface Analysis group at NPL in 2006-7 gave a great impact to me in a good way and I really enjoyed UK/London life whilst I was there. Fortunately, around the end of the working experience, Prof. John F. Watts offered a PhD studentship, so I decided to study surface science in University of Surrey, which was my big turning point in my life.

What’s it like working at Ionoptika?

All colleagues here in Ionoptika are friendly, so I enjoy chatting with them at the office. So I miss it very much because of the current WFH situation…

What has been your best memory or achievement in your career?

It would be my first poster award in SIMS-XVII. On the day for the award ceremony, I was late to get to the venue, because I didn’t care for the ceremony at all (a naughty student!). When I got into the venue and tried to find a space to sit, the chairman (coincidentally it was John, my supervisor) on the stage, said ‘Naoko, you are there!’. Everybody turned back and looked at me. I was so proud of my work on the stage, but I felt so embarrassed as well…

What do you enjoy doing in your spare time?

Aromatherapy and reading books.

Have you been doing anything interesting/different/new to cope with the lockdown?

I’ve started online yoga lessons. I still prefer to do it in an actual studio with people, but online yoga class works at least. 

What are you looking forward to most once the lockdown is over?

Travel to see my family and friends all over the world. Miss you all very much!

You can catch up with Naoko and the rest of the Ionoptika team at various conferences throughout the year. Interested in becoming part of our team? Visit our Careers page.

RADIATE: Research And Development with Ion Beams – Advancing Technology in Europe

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RADIATE logo

Ionoptika has joined forces with 14 partners from public research and 3 other SMEs for the RADIATE project, exchanging experience and best practice examples in order to structure the European Research Area of ion technology application.

Besides further developing ion beam technology and strengthening the cooperation between European ion beam infrastructures, RADIATE is committed to providing easy, flexible and efficient access for researchers from academia and industry to the participating ion beam facilities. About 15,800 hours of transnational access in total is going to be offered free of charge to users who successfully underwent the RADIATE proposal procedure.

Joint research activities and workshops aim to strengthen Europe’s leading role in ion beam science and technology. The collaboration with industrial partners will tackle specific challenges for major advances across multiple subfields of ion beam science and technology.

RADIATE aims to attract new users from a variety of research fields, who are not yet acquainted with ion beam techniques in their research, and introduce them to ion beam technology and its applicability to their field of research. New users will be given extensive support and training.

The project is monitored by an External Advisory Board for quality assurance and guidance. Users with accepted proposals for RADIATE’s transnational access program are selected by an external user selection panel to ensure an unbiased and fair selection process.

RADIATE is building on the achievements of SPIRIT (Support of Public and Industrial Research using Ion Beam Technology), a previous EU funded project coordinated by the Helmholtz-Zentrum Dresden-Rossendorf (HZDR). SPIRIT ran from 2009 to 2013 and united 7 European ion beam centers and 4 research providers.

To learn more about RADIATE or to get involved, please visit the website.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 824096

Featured ImageIonoptika Ltd 2020

High-resolution molecular imaging ToF SIMS

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Historically ToF SIMS has not been sensitive to intact molecules due to the excessive fragmentation caused by the primary ion beam. Now however, thanks to the progress in gas cluster ion beam (GCIB) technology over the last decade, sensitivity to intact molecular species in ToF SIMS has increased by several orders of magnitude, making it possible to achieve molecular imaging with the high-spatial resolution traditionally associated with SIMS.

The development of high-energy gas cluster beams with small spot sizes has dramatically altered the sensitivity to intact molecular species. This is enabled by the unique design of the J105 SIMS, which allows any ion beam to be used without impacting performance. So large gas cluster beams may be used while still maintaining high mass resolution, and thereby greatly improving molecular sensitivity.

It is now possible to map the distribution of lipids in biological tissue with higher resolution than ever before. This is illustrated in Figure 1, where two sphingolipid species and a glycerophospholipid species are imaged within rodent cerebellum tissue. The inset line scan demonstrates the sharp drop off in C24-OH signal, on the order of a few microns, giving researchers unparalleled clarity into the structure of their sample.

Figure 1. 2 μm per pixel lipid mapping in rodent brain tissue, analysed using a 40kV Ar4000 beam. Boundaries between sphingolipid species C24 (m/z 890.6 – blue), and C24-OH (m/z 906.6 – green), and the glycerophospholipid species PI(38:4) (m/z 885.6 – red) are clearly resolved. Inset: line scan drawn across the C24-OH signal. Data courtesy of the University of Gothenburg.

As damage to the sample molecules is minimised, a volume of material can be analysed, not just a static dose limit, resulting in higher signals and the ability to depth profile without wasting material. Significantly, for a given dose, larger cluster beams have been shown to produce higher signals from most large molecules, as illustrated in Figure 2.

Figure 2. High signal intensity with low fragmentation. (a) Normalised signal intensity for molecular and significant fragment signals from Irganox 1010 with an Ar4000 beam, showing much higher ion yields for higher beam energy. (b) Normalised signal ratios comparing levels of fragmentation for four different beam energies. Data courtesy of the University of Gothenburg.

Figure 3 shows the mass spectrum and corresponding image of the DG region of a rodent hippocampus. Using a 30 kV [CO2]3k+ beam, the distribution of GM1(36:1), GM1(38:1), and ST(18:0) were mapped at a pixel density of 2 μm per pixel. A wealth of information is contained within the spectrum, with detailed phospholipids, cardiolipin species, and high-mass ganglioside species all clearly present and identified.

Figure 3. Negative SIMS spectrum and corresponding image from DG region of rodent hippocampus, showing the range of phospholipid, ganglioside, and cardiolipin species detected. Analysis performed using a 30 kV [CO2]3k+ beam at 2 μm per pixel. Data courtesy of Pennsylvania State University.

Large molecular species such as lipids play an important role in basic cellular processes. As such it is crucial to have the correct tools with which to study these systems. The J105 SIMS, alongside the development of new gas cluster ion sources, is pushing the capabilities of ToF-SIMS, both in terms of the mass detection limits, and the limits of spatial resolving power, enabling researchers to probe further and discover more.

For further information about our instruments or to arrange a demonstration, please get in touch via our Contact page.

Cherry blossoms mount fuji

Detecting pollutants in a Cherry Blossom leaf

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Plant samples such as leaves are a challenging sample for ToF SIMS. Composed of insulating materials such as cellulose (cell walls) and lipophilic coatings (cuticular layer), charge build up can affect measurement quality. Using an electron gun during analysis can alleviate the charging effect and enables 3D analysis of the surface of a leaf.

Cherry blossom leaves (Prunus serrulata) collected in a busy city were analysed on the J105 SIMS using a 40 kV C60 ion beam. Pieces of blossom leaves were mounted onto double sided tape, attached to a sample stub, and gently pressed down in the corners to ensure best possible contact without deforming the leaf surface. Overview images were acquired on both sides of the leaf surface, with a spatial resolution of 1 µm per pixel and a primary ion dose of 2.2×1013 ions/cm2.

Experimental Conditions

Ion Beam:40kV C60+
Dose:2.2×1013 ions/cm2
Spatial Resolution:1 μm
Charge Compensation:60V Electron Gun, 25V Stage Bias

Without charge compensation, no secondary ions could be detected. Applying an ever-increasing stage bias would produce secondary ions temporarily. Only a combination of charge compensation methods via a 25 V pulsed stage bias and electrons emitted at 60 V beam energy enable us to generate an image of the leaf surface as well as steady signal during depth profiling.

Figure 1. Analysing the surface of a cherry blossom leaf.

Surface analysis reveals the outline of single plant cells. The outlines of the cells contain CaOH (m/z 56.97), while inorganic compounds such as K2O+ (m/z 93.92), Na2Cl+ (m/z 80.95), and Fe+ (m/z 55.93) are unevenly dispersed on the surface of the leaf. All compounds identified across the uneven leaf surface have a mass accuracy < 5 ppm (Table 1).

Analysis also revealed the surface to be coated with an even layer of organic compounds represented by molecules containing aromatic structures, e.g. tropylium ion, C7H7+ (m/z 91.05). Wax coatings on plants take the form of long aliphatic carbon chains, so aromatic structures such as these are unexpected and may indicate the presence of gasoline pollutants such as BTX (benzene, toluene, xylene).

Analysis of complex, insulating, and uneven samples such as these is made routine on the J105 SIMS.

Depth profile analysis reveals that as the cells are etched away, the layer of aromatic compounds reappears on the underside of the sample. Additionally, potassium containing substances are detected that are not present on the surface and only occur within certain cell walls (Figure 1 inset, green).

Imaging depth profile through a leaf showing CaOH (red), K2O (green), and C7H7 (blue).

Repeating the analysis on the lower epidermis reveals a high concentration of aromatic signals surrounding the stomata (Figure 2, green). It is known that plants can absorb pollutants such as BTX, mainly through the stomata, giving further evidence to the origin of these compounds.

Analysis of lower epidermis. Concentration of aromatic signals such as C7H7+ around the stomata may indicate uptake of pollutants such as BTX.

Analysis of complex, insulating, and uneven samples such as these is made routine on the J105 SIMS. Performing high-resolution 3D analysis with high sensitivity creates a more complete picture, enabling a greater understanding of the sample and its environment.

We gratefully acknowledge NESAC/BIO and the University of Washington for the use of their data in this work.

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