The team believes that ultra-thin gold nanowires can be used to electrically sense the presence of small quantities of biomarker proteins found in the bodies of men suffering from certain forms of testicular cancer.
The sensor will pass a tiny current through the nanowire, which has been engineered to attract the human chorionic gonadotropin (HCG) protein; a hormone that is secreted when a patient is suffering from testicular cancer. The team hopes to be able to detect a change in the electrical current flowing through the wire when HCG proteins attach themselves to it.
Dr Kevin Critchley, project leader from Leeds University’s department of physics and astronomy, told The Engineer that gold nanowires with the required 3nm diameter could be produced relatively easily in a beaker through a simple chemical reaction.
‘We use gold chloride with a solvent called alkylamine,’ he said. ‘The gold chloride will very slowly reduce to gold metal while the alkylamine acts as a kind of template that makes these very small wires that are only several microns in length.’
He explained that current procedures used to detect testicular cancer involve sending samples away to a specialist laboratory and getting results back can take ‘quite some time’.
‘The idea was to go more towards something that would give you a measurement in a GP’s surgery or an off-the-shelf device similar to a pregnancy test,’ said Critchley.
To complement Critchley’s work, computational models will be developed by Prof Mike Payne at Cambridge University’s department of physics to provide a detailed fundamental understanding of the sensing capability of ultra-thin nanowires.
Testicular cancer is the most common cancer found in males aged between 20 and 39 years. Around 2,000 men are diagnosed with the disease every year in the UK, but advances in treatments means that more than 95 per cent of them are now cured. Early detection of the cancer has sufficient benefits to the patient because the treatment is less complicated and can be performed without having a significant effect on fertility.
‘This research needs more work before we know whether it could form the basis for a useful test to detect testicular cancer earlier,’ said Laura McCallum, science information manager at Cancer Research UK. ‘Steps to improve the early detection of testicular cancer could mean less aggressive treatments for some men, reducing side effects, but HCG is only elevated in some men with the disease and so a test based on this wouldn’t spot everyone.’
Beyond the research programme, the team hopes to extend the biosensing capabilities of nanowires to detect other cancers and diseases.
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