Tomorrow's Health, Today's Research

Dr Reuven Gordon

Professor, Department of Electrical & Computer Engineering
Canada Research Chair in Nanoplasmonics
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Phone: 250-472-5179
Lab Page
Research area: Nanophotonics, plasmonics, biophotonics, biosensors, optical trapping, lab-on-chip devices, nanotechnology and nanofabrication. 

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Research Profile:
Thinking Big but on a Small Scale: Using nanostructures and optical manipulation to study viruses and improve the early detection of cancer

“Where can the things I do, and the stuff I make, be used to improve people’s lives in the most meaningful way?”

This is the question that is often at the heart of the research that Dr. Reuven Gordon, both an engineer and a physicist, conducts as the Director of the University of Victoria’s Nanoplasmonics Research Laboratory. Gordon’s expertise lies in the field of nanoplasmonics, or more simply put, the study of how light behaves in the presence of tiny particles of metal.

Early Detection of Cancer. Gordon, in collaboration with the Vancouver-based company Biomark Technologies Inc, is working hard to create a simple screening test that will help clinicians detect the presence of hidden cancers at a much earlier stage. Gordon is developing a unique method of detecting and quantifying extremely small amounts of an exogenous biomarker that, when detected in human urine, may indicate the presence of cancer.

Traditional methods of biomarker detection rely on Raman spectroscopy technology, which uses light to induce a molecular vibration pattern that is unique to each molecule. This distinct signal is related to the intensity and wavelength of the scattered light and is akin to a ‘molecular fingerprint’. The drawback, however, is that Raman is not sensitive enough to detect small quantities of anything.

In order to overcome this problem, Gordon has incorporated the use of metal nanoparticles, in particular tiny particles of gold, that have properties that make them very sensitive to optical scattering. Acting like tiny optical antennae, these nanoparticles also have directivity features that increase signal strength and facilitate the detection and quantification of even trace amounts of the biomarker. Gordon’s Directivity Enhanced Raman Scattering (DERS) technology is so effective it has actually demonstrated single-molecule sensitivity.

While Gordon is currently in the process of validating this new biosensor technology, we could soon see its adoption in the clinical world. This rapid, efficient, and affordable screening test will help clinicians detect cancer much earlier — and an early diagnosis leads to a better prognosis.

 

Optical Trapping. In order to study the tiniest of things, one must first capture them. Gordon has created an innovative technique that allows researchers to study tiny particles in their natural, ‘untouched’, state. Standard methods of studying bacteria and viruses involve complicated binding events in finicky environmental conditions in order to ‘stick things down’ and make them ‘visible’ to us. These processes ultimately change the very nature of the particle under study. Gordon has developed an optical trapping method that is free of these complications and capable of capturing particles (such as bacteria, viruses, and single proteins) that are 10,000 times smaller than the width of a human hair.

Optical trapping relies on the momentum of photons, or in simpler terms, discrete packets of light, to push the desired particle into the field of focus. Physics dictates that the smaller the particle, the poorer its efficiency at scattering light. Trapping extremely small particles requires so much light intensity and energy that the particles end up, essentially, exploding. This places a limit on the size of particle that researchers can study with simple optical rapping.

 

The solution to this dilemma lies in nanotechnology and Gordon’s newest invention; a tiny chip consisting of a thin plate of glass covered in a layer of gold with a small aperture, or nanohole, in the middle. This nanohole results in an ‘aperture effect’ that essentially counteracts this ‘small particle-ineffective scattering’ problem. This innovative chip enables researchers to trap and ‘see’ particles on such a small scale that they are capable of studying a single protein. This helps scientists better understand a protein’s structure and function (particularly in relation to folding, unfolding, and binding events) and is essential to the development of new and effective pharmaceutical drugs.

Optical Tweezers. Gordon is also in the process of developing optical nanopipettes that are capable of isolating and moving particles as small as a single virus. You can think of these aperture-equipped, glass fiber probes as the equivalent of a tiny pair of extra strong, fine-tipped tweezers. The ability to ‘pick out’ a single particle and move it to a new location comes in handy when studying viruses, which present researchers with an extra challenge, given their tendency towards rapid mutation and great heterogeneity within a population.

Gordon’s research has significant applications in the biomedical world and has the potential to positively influence both drug development and cancer detection. So what are the factors that might limit wide-scale adoption of Gordon’s innovative ideas and technologies in the real world?

“None. I don’t see any barriers. If there is one, it is simply getting the message out there,” says Gordon.