Bioaffinity detection and tracking of disease biomarkers via dynamic multi-modal surface plasmon enhanced nanoscopy

The ability to directly monitor biomolecular interactions (e.g. DNA-DNA, RNA-DNA, protein-protein) in real-time is of great importance to many areas of biology and medicine. At the cellular level, very few molecules can be responsible for inducing a significant biological response and there remains an urgent need for highly sensitive optical methods able to both identify and spatially track multiple target biomolecules simultaneously in complex and dynamic biological environments. To address this challenge we propose to develop a unique multi-imaging platform capable of monitoring large numbers of individual, freely moving nanoparticles and monitoring their interactions with target molecules and other nanoparticles. This new technology will initially be applied to the multiplexed detection of microRNAs with the distinct advantage of not requiring either target pre-modification or subsequent amplification steps to achieve the sensitivities necessary for the direct analysis of genomic RNA samples. The research takes advantage of the electronic properties of metallic nanoparticles that are associated with greatly enhancing the intensity of various types of spectroscopic signals such as scattering, Raman and fluorescence. These signals are highly responsive to changes in the immediate environment around each nanoparticle with Raman in particular providing a molecular fingerprint useful for identification. However, typical investigations involve applying only one of these spectroscopic modalities and either looking at select individual particles immobilised on a surface or acquiring an ensemble-averaged spectrum of the bulk sample. Imaging is a particularly powerful and intuitive approach for investigating complex systems. The radically different multi-spectroscopic methodology proposed here enabling the high-throughput visualisation of individual particles along with rapid optical discrimination between different particles sizes and clusters is expected to have a far-reaching impact. In addition to creating a powerful tool for bioanalytical investigation, this research will open up significant new opportunities to physicists, chemists and engineers interested in the functionalisation and assembly of nanoparticles to create next generation materials and devices.

The development and exploitation of new nanotechnologies is already beginning to have a far-reaching impact at multiple levels of society including governmental, academic, the commercial sector, as well as the wider public. The proposed research into creating new nanoparticle-enhanced methodologies for dynamically detecting and tracking biomolecular interactions at unprecedented sensitivities and spatial resolutions overlaps with several priority areas stipulated by the UK government and funding research councils. These include nanometrology where there remains a real need for quantitative methods for real-time nanoscale measurement in complex wet environments that will facilitate future research in many biotechnological fields such as medical therapeutics, nanotoxicology and drug delivery. In particular, creating new methodologies for the multiplexed direct detection of disease biomarkers at ultralow concentrations will, in the longer term, lead to earlier diagnosis, more effective treatments and better understanding of disease pathways. These important economic and societal benefits, among others, were recently outlined in the EPSRC's Nanotechnology Grand Challenges in Healthcare. At an industrial level, it is imperative that the UK maintains a leading position in discovering and applying new and emerging technologies. A strong focus on application outcomes in combination with a sound fundamental scientific drive has been a consistent theme of my research in recent years, as demonstrated with 3 US patents and the opportunity to work with a company to develop one of these to a commercial product. This awareness continues in the proposed research with the direct involvement of the company Nanosight Ltd who have demonstrated a committed interest in the research outcomes. Prior to publication of any new research, an assessment on its potential for commercialisation will be made and any new IP developed will be handled via the university's Research and Innovation Department. Another significant benefit to the private sector is that students (postgraduate and undergraduate) participating in the proposed research will be exposed to a variety of biological, material and optical related scientific disciplines besides chemistry. Cross-disciplinary skills and broad experience are becoming ever more important as traditional research barriers are removed and are highly sought after by companies seeking a more adaptable workforce. I am a strong proponent of encouraging undergraduate participation in meaningful research having published my first papers at this level and will actively encourage undergraduates to apply for vacation scholarships and bursaries. Dissemination of research activities and outcomes will be performed at multiple levels aimed at maximising research impact and encouraging public interaction. One approach in which I have already become very active is schools liaison with a particular focus on supporting chemistry teachers by creating new research projects for Advanced Higher students. During the funding period, aspects of my research interests will be adapted to create simple and safe investigative projects that will be distributed to a growing number of schools who have expressed an interest in such support materials. I will also encourage pupils as well as teachers to contact me directly and/or visit the Dept as part of the support. Further opportunities to engage the general public such as following the publication of groundbreaking results in leading journals will be exploited by promptly communicating to the university's press office and the EPSRC as well as via personal, academic and professional websites and forums.