New ‘lab-on-a-chip’ aims for portable diagnostics

A new lab-on-a-chip test has been developed at Imperial College London that aims to pave the way for low-cost handheld infectious disease testing.

The chip, known as ‘TriSilix’, is a ‘micro laboratory’ reportedly able to perform a miniature version of the polymerase chain reaction (PCR) on the spot, with results present in ‘a matter of minutes.’ Each lab-on-a-chip contains a DNA sensor, temperature detector and heater to automate the testing process, with a typical smartphone battery able to power ‘up to 35 tests’ on a single charge.

PCR detects viruses and bacteria in biological samples such as bodily fluids, faeces or environmental samples and is usually performed in a laboratory, meaning test results aren’t immediately available.

Researchers are said to have developed a series of methods to produce the chips, made from silicon, in a standard laboratory rather than large cleanroom facilities. Researchers claim to have cut the costs and time it takes to fabricate the chips, enabling the potential for them to be produced anywhere in the world.

Image credit: Imperial College London

Lead researcher Dr Firat Guder of Imperial’s Department of Bioengineering explained how patients could use the lab-on-a-chip for testing rather than going to a clinic and sending swabs to a lab.

“You would use the test much like how people with diabetes use blood sugar tests, by providing a sample and waiting for your results – except this time it’s for infectious diseases,” he said.

According to the team, they have used TriSilix to diagnose a bacterial infection mainly present in animals as well as a synthetic version of the genetic material from SARS-CoV-2, the virus behind COVID-19. Researchers said that the system could in future be mounted onto handheld blood sugar test-style devices, allowing people to test themselves and receive results at home for colds, flu, recurrent infections like those of the urinary tract (UTIs) and COVID-19.

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It is hoped that this ‘highly portable’ test could accelerate diagnosis of infections and reduce costs by eliminating transportation of samples, researchers added. Such tests could be performed in the absence of medical professionals, allowing for self-isolation to begin immediately to minimise the risk of infecting others. 

People in rural areas of lower-income countries could especially benefit due to the expense and practicality of travelling to a clinic for testing.

“Monitoring infections at home could even help patients, with the help of their doctor, to personalise and tailor their antibiotic use to help reduce the growing problem of antibiotic resistance,” commented first author Dr Estefania Nunez-Bajo, also of the Department of Bioengineering. 

Next, the researchers plan to validate their TriSilix chip with clinical samples, automate the preparation of samples and advance their handheld electronics. They are currently looking for partners and  to begin delivering testing at resource-limited settings.

The research was funded by Wellcome Trust and has been published in Nature Communications.