The Soft Condensed Matter (SCM) Village at Diamond Light Source provides scientific capabilities for the investigation of biological samples and inorganic systems using infrared (IR), ultraviolet (UV) and X-ray radiation. The SCM village consists of four beamlines divided into the two X-ray scattering beamlines (B21 and I22) and spectroscopy beamlines (B22 and B23). Together, these beamlines can provide experimental investigations on samples in the solution state, fixed inside living cells or deposited as thin-films.
One of the most noticeable changes to the village over the past few months is the renewal of a dedicated laboratory space for users. While temporally located in a building outside, users now benefit from a brand new laboratory right next to the beamlines. The laboratory houses vital equipment for sample preparation and analysis such as a centrifuge, a small tissue-culture facility, spectroscopy equipment (including circular dichroism, standalone infrared and UV spectroscopy, multi-angle and quasi-elastic light scattering) and the ability to work with different gases. The equipment in the lab can be booked ahead of time when requesting access to the beamline and can be used during periods of beamline shutdown.
Figure 1: Two new labs have been renovated and dedicated to the Soft Condensed Matter Village.
The Synchrotron Radiation Circular Dichroism (SRCD) beamline (B23) is the only CD beamline in the world that offers greater imaging capabilities than bench-top CD instruments. Operational since 2009, B23 allows users to characterise the structure of complex materials in solution and in solid state films using circularly polarised light. This technique is important for analysing changes in the chirality of molecules that includes changes to the conformation of nucleic acids, carbohydrates and proteins.
Over the past year, B23 has seen the introduction of a unique customised sample cell. The fused silica cells were designed by Principal Beamline Scientist, Dr Giuliano Siligardi, to maximise the signals obtained from samples that have a high salt content, such as those arising from biological systems. The specialised sample cells utilise an ultra-thin path length to minimise the absorption from salt, and the new design also removes a frustrating bottleneck for users, as they can be cleaned more efficiently than before. Users with many samples in particular will benefit from the increased throughput on this beamline.
The Multimode Infrared Imaging and Microspectroscopy (MIRIAM) beamline (B22) is used to assess the molecular composition and microscopic spatial distribution of a sample at the highest resolution optically achievable. It has two end stations that are dedicated to confocal IR spectromicroscopy and IR imaging, with a suite of single and array detectors that cover the whole IR range.
B22 is used for a wide variety of applications such as the analysis of inorganicorganic combinations and polymers, as well as studying live cells in situ. B22 has seen a fundamental improvement this year, with the upgrade of the flooring in the entire beamline. The floor has been sealed in epoxy to raise its biosafety rating to level 2, which means that users can now conduct experiments with living cells to monitor drug efficacy in real-time.
More importantly, B22 now houses an atomic force microscope, which can be combined with IR microspectroscopy to greatly increase the resolution of measurements by hundreds of nanometers compared with synchrotron IR alone. Pioneered by Principal Beamline Scientist, Dr Gianfelice Cinque, the new setup enables users to scan across the surface of a cell to yield quantitative spectroscopic data at the nanoscale and beyond the diffraction limit of light. This powerful technique can discriminate between aqueous and lipid structures to visualise the organelles within a living cell.
Figure 2: Microfluidic device placed in the customised vertical chamber on B23.
The Small Angle Scattering (SAPPHIRES) beamline (I22) offers combined Small and Wide Angle X-ray Scattering studies (SAXS and WAXS) on a range of low order biological and synthetic samples. It is particularly adept at providing structural information on partially ordered materials to garner details on nanoparticle sizes or hierarchical structures.
One of the more comprehensive upgrades to I22, completed this year, is the introduction of Grazing Incidence SAXS (GI-SAXS). This upgrade, led by PDRA Paul Staniec, has taken several years to complete and now offers a wealth of new capabilities at the beamline. GI-SAXS is used for monitoring the surface structure at the nanoscale and can yield important information on thin films in fields of science such as photovoltaic devices and self-assembly nanostructures.
I22 also now benefits from an in vacuum WAXS detector. In collaboration with DECTRIS, a large l-shaped detector was built that interfaced directly to the vacuum, which means that users can obtain partial 2D WAXS data from a sample while still benefiting from the full 2D SAXS data collection already available.
The High Throughput SAXS beamline (B21) is used for the study of particles in a solution. This technique is typically used by biologists where crystallography is not an option and it can provide valuable structural data on the thermodynamic state of a sample. The end station at B21 can be configured for full automation using the BIOSAXS robot using 96-well plates to enable high throughput screens.
Recently, B21 has experienced a huge overhaul, with a total upgrade of its X-ray optics from a double crystal monochromator to a double multilayer monochromator. The upgrade has increased the X-ray intensity by over 80- fold and improved the signal-to-noise ratio in the region of 150 to 200 fold. The massive improvements in intensity have reduced sample measurement times from 3 minutes per sample down to 1 second per sample. Moreover, the instrument has been stripped back and rebuilt entirely to improve focussing and reduce background scattering. Together, these improvements have made B21 one of the most sensitive beamlines in the world. Samples can now be imaged at concentrations 10–20 times lower than before, a feature that is ideal for users with dilute samples that are unable to be concentrated.
Diamond Light Source is the UK's national synchrotron science facility, located at the Harwell Science and Innovation Campus in Oxfordshire.
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