High-Throughput Diagnostics with Chiral Plasmonic Assays

Lead Research Organisation: University of Glasgow
Department Name: School of Chemistry

Abstract

Biological structure of proteins determines their functionality. It dictates how the proteins interact with other molecules, which is significantly important in medical diagnostics that use proteins to detect markers for disease or modern therapeutics where drugs will interact with proteins in the body. Determining the changes to a protein structure can be extremely useful in improving diagnostic capabilities by simplifying current chemical tests so that clinicians can get results faster and with added information about how the proteins interacted. This can improve their ability to diagnose patients and provide appropriate medication immediately. With the inexorable emergence of antimicrobial-resistant pathogens, this would be extremely useful to curtail excessive antibiotics. However, determining the structure of a protein requires detailed, tedious and expensive techniques such as x-ray crystallography. Optical spectroscopy techniques are not sensitive to the entire structure of a protein and all these methods require large sample quantities, eliminating their use for rapid routine diagnostics. I propose to develop and exploit a new class of label-free biostructure sensitive tests (assays) for diagnostics based on the novel phenomenon of chiral plasmonic sensing. This technique, discovered through EPSRC funded research, is capable of rapidly sensing conformational (structural) changes in a monolayer of biomolecules. The proposed "Chiral Plasmonic Assays" (CPAs) will enable applications such as detection of multiple pathogens and improve drug discovery techniques. These unique assays will use conformational changes to detect biophysical activity and provide insight into the behaviour of the molecular structure for rapid routine diagnostics. CPAs will be sensitive to picomole quantities of the target in clinical samples (blood serum, saliva) without complex flow systems, hence overcoming the limitations faced by current optical techniques such as surface plasmon resonance. CPAs will mitigate the need for multiple chemical steps that are required in popular chemical assays and require minute sample quantities without multiple reagents and problems like cross-reactivity. Using unique templated plasmonic devices pioneered in Glasgow, made using the same technology as Blu-ray discs, chiral plasmonic assays will be low-cost, high-throughput diagnostic kits. This innovation will use rapid imaging tools developed through funding from QUANTIC (EPSRC) with industrial partners HORIBA Scientific and cutting-edge customisable protein technology developed by industrial partner Avacta Life Sciences to achieve highly multiplexed diagnostics. In particular, this research will develop CPAs to detect diseases like sepsis, a leading cause for hospital deaths and invasive aspergillosis, a fungal infection that plagues cancer patient undergoing chemotherapy. This technology will penetrate into the label-free diagnostic market (>£1 billion by 2022) and in vitro diagnostics market worth over £40 billion, supporting UK's position as a leader in healthcare technology. This fellowship will enable myself to dedicate my time and provide resources to develop and prove this revolutionary new diagnostic platform that will fuel my entrepreneurial ambitions to change our current approach to biochemical diagnostics.

Planned Impact

The innovation of chiral plasmonic assays is a new paradigm in biosensing. This concept can revolutionise how biophysical interactions are detected impacting diagnostics that span over multiple biologically relevant applications. The direct output of this fellowship would have significant impact on healthcare through the prominent applications of medical diagnostics that will aid clinicians in making improved decisions in shorter timescales, hence improving quality of patient care. With the undesired emergence of antimicrobial-resistant pathogens, such technology can aid to curb the use of unnecessary antibiotics as outlined by the world health assembly in 2015. The research focuses on five specific cases that are examples of where CPAs would benefit healthcare by better informing clinicians. These include:
1) Sepsis, a leading cause of hospital deaths and severe morbidity Research in rapid diagnostics of sepsis is a high priority.
2) Invasive Aspergillosis (IA), a life-threatening fungal infection in patients with a weakened immune system. Unable to rapidly detect IA, clinicians prescribe broad-spectrum antibiotics to safeguard patients risking growth of antimicrobial resistance.
3) Streptococcal infections are common bacterial infections behind a wide range of upper respiratory tract infections that can be difficult to distinguish from viral infections and requiring time consuming laboratory for diagnosis.
4) Clostridium difficile infections (CDI), a bacterial infection and one of the leading causes of hospital deaths in the UK and US. Particular hypervirulent strains are significantly dangerous and a problem for infection control requiring rapid diagnostics for CDI.
The NHS UK spends approximately £22 billion per year on goods and services. Rising demands and associated costs are being fuelled by an aging population, increase in chronic disease and higher expectations to name a few. With tightening budgets and global uncertainty, the need for reducing costs and improving efficiency in the healthcare system is paramount to insuring its survivability over the next few decades. CPAs can assist by reducing the overall diagnostic costs. An efficient low cost highly multiplexed system would not only reduce costs for individual tests but also reduce the burden on staff.
Furthermore, as modern therapeutics shift towards the use of protein and biomolecular therapeutics (biopharmaceuticals), optimisation of the protein behaviour (that is dependent on the structure) against targets is essential. Once again, a rapid biostructure sensitive assay would reduce optimisation time and costs. This would trickle down to reduce costs of the drugs as well. Hence, use of CPAs as a cutting edge tool for improving current drug optimisation methods would benefit healthcare.
CPAs will exploit a label-free diagnostics market expected to be worth >£1billion by 2022. The in-vitro medical diagnostics market is expected to be worth over £40billion by 2021. Successful products such as CPAs would bring significant revenue to the UK economy along with prospective jobs. It would enhance UK's standing as a global leader in healthcare technology.

Publications

10 25 50
publication icon
Gilroy C (2020) Active Chiral Plasmonics: Flexoelectric Control of Nanoscale Chirality in Advanced Photonics Research

publication icon
Gilroy C (2019) Roles of Superchirality and Interference in Chiral Plasmonic Biodetection in The Journal of Physical Chemistry C

publication icon
Kakkar T (2020) Superchiral near fields detect virus structure. in Light, science & applications

publication icon
Kelly C (2018) Chiral Plasmonic Fields Probe Structural Order of Biointerfaces. in Journal of the American Chemical Society

publication icon
Rodier M (2019) Probing Specificity of Protein-Protein Interactions with Chiral Plasmonic Nanostructures. in The journal of physical chemistry letters

 
Description Currently, we have been able to achieve repeatable results of detecting protein binding to the surface with our sensor. Our success has been achieved with the slight alteration from our proposed strategy in how we would have measured the optical response from our structures but this should not affect the applications we aimed for. Our structures show improvement on commercially available systems due to the plasmonic nanostructure design. This includes higher surface sensitivity, ability to detect small molecule binding and ability to work without complex microfluidic systems. Small molecule detection, in particular, is quite important as small molecules do not change the refractive index drastically and hence current optical techniques in the market find it difficult to detect such protein-small molecule interactions. Furthermore, we have already been successful in multiplexing, that is detection specific binding of different proteins in a single experiment. We are working towards publishing these results.

My joint proposal with the centre for virus research to use this system for diagnostics related to the COVID-19 outbreak has been funded and we are able to detect proteins relevant to influenza and corona (SARS2) viruses. Our next step is to detect the liposomes and inactivated viruses to ascertain the biosensing of virus markers and entire virus particles. Once we succeed here, we will shift the instrument to the centre for virus research and evaluate its performance against actual samples acquired from the NHS. By June this year, we intend to have achieved a proof of concept of a muti-virus detection assay with this technology.
Exploitation Route I continue to work with HORIBA Scientific who are still keen on this technology. The developed system is also being primed for use in the veterinary and virology groups at the University of Glasgow for their applications as demonstrations. It is expected that by the end of the year we will have results using this system for research work specific to our collaborators that should help show the impact of the technology in research and create a market application example.
Following the results of the multi-virus detection work, and the multiplexing, we intend to have a more advanced proof of concept for the assay tested against real samples pre-tested by our NHS colleagues to compare with current diagnostic techniques. Based on this, we should have an assay with translation completed and now ready to pursue funding for commercialisation.
Sectors Agriculture, Food and Drink,Healthcare,Pharmaceuticals and Medical Biotechnology

 
Description University of Glasgow Wellcome Trust Translational Partnership
Amount £800,000 (GBP)
Funding ID 219390/Z/19/Z 
Organisation Wellcome Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 03/2020 
End 02/2022
 
Title PLASMONIC DEVICE, METHOD OF MANUFACTURING A PLASMONIC DEVICE AND METHOD OF ANALYSIS USING A PLASMONIC DEVICE 
Description A plasmonic device is disclosed, the plasmonic device having a base substrate and an electrically conductive film formed on the base substrate. The base substrate has a reference upper surface and an arrangement of chiral nanostructures formed in relief from the reference upper surface. Each chiral nanostructure has a nanostructure upper surface which is disposed at a distance of at least 30 nm from the reference upper surface in a thickness direction. The electrically conductive film is formed on the nanostructure upper surface of each chiral nanostructure and on at least part of the reference upper surface of the base substrate. Also disclosed is a method of analysis of a biological material using the plasmonic device, by depositing the biological material onto the plasmonic device and irradiating the plasmonic device and the biological material with electromagnetic radiation. The arrangement of chiral nanostructures and electrically conductive film generates a superchiral electromagnetic field, the effect of the presence of the biological material on the superchiral electromagnetic field then being detected. 
IP Reference US2017370923 
Protection Patent granted
Year Protection Granted 2017
Licensed No
Impact The patent puts us in a strong position to help commercialise the work either with our partners HORIBA or through a spin-out that is now being planned over the summer.