AgPlus Diagnostics

Making rapid, portable diagnostics possible

National Physical Laboratory

Faster point-of-care diagnostics will allow earlier interventions to treat illness, and reduce patient anxiety associated with waiting for test results. AgPlus has developed a portable diagnostic platform which can quickly identify a wide range of illnesses from a blood or saliva sample, allowing rapid point-of- care diagnosis.

Tim Dwyer, Research and Development Director at AgPlus Diagnostics said:

“Working with NPL gave us access to the latest chemical analysis technology which allowed us to solve a problem well beyond our capabilities and identify a solution. This overcame a major roadblock to manufacturing the final product on a commercial scale.”

NPL helps AgPlus solve materials chemistry challenge, unblocking the route to mass producing its diagnostic devices. Faster point-of-care diagnostics will allow earlier interventions to treat illness, and reduce patient anxiety associated with waiting for test results.

Faster point-of-care diagnostics will allow earlier interventions to treat illness, and reduce patient anxiety associated with waiting for test results. AgPlus has developed a portable diagnostic platform which can quickly identify a wide range of illnesses from a blood or saliva sample, allowing rapid point-of- care diagnosis.

They have been licensing their technology for R&D applications within human clinical diagnostics, and now expect to launch the first mass-produced diagnostic tool for clinics and hospitals in 2019.

Their technology uses an innovative diagnostic technique. Silver nanoparticles are coated with an antibody which makes them bind to compounds in the sample which are indicative of particular diseases. The number of silver nanoparticles, after being separated from those that didn’t bind, is proportional to the amount of compound in the sample – which can then be linked to a condition. Measuring the nanoparticles involves changing the voltage across two electrodes, which changes the silver nanoparticles into silver ions. Measuring the charge of these ions shows their quantity.

Challenge

AgPlus had an issue with the mass production of their electrodes. They were produced with a printing process, but there were issues with consistency, leading to unacceptably high rates of failure. AgPlus, as a small business, did not have the advanced analytical technology needed to identify the source of the problem, or the quality control technology to identify poorly performing electrodes before the device was assembled.

Solution

NPL examined batches of electrodes using advanced analysis methods, including 3D microscopy, elemental analysis, electrochemical impedance spectroscopy and electrochemical imaging – techniques beyond the capabilities of AgPlus’ inspection facilities. The electrodes were rough, so it was necessary to measure the thickness in several ways to get conclusive values. The two organisations characterised the electrodes, identifying the correlation between structure, electrochemical performance and chemistry of various electrodes.

The research found the printing thickness to be unsuitable – the roughness of the electrodes was too great for the existing nominal thickness to consistently fully coat the sensor. Batches were then created with different thicknesses – NPL and AgPlus carried out further measurements to identify the optimal thickness to give confidence in the end product.

Impact

The project improved electrode design, reducing failure rates to the levels needed as they scale up to mass production. The project also identified changes to their quality control methods which have saved time and improved productivity.

This gives AgPlus greater confidence in the performance of its product and in its manufacturing processes as it brings the product to market.

“AgPlus, although originally spun out of NPL, has had limited contact since.
The engagement has been a valuable reintroduction to NPL, helping us understand their wide-ranging capabilities. As we advance as a company, it is invaluable to know we can call on NPL for measurement challenges like this. We anticipate working with them much more in future to address complex measurement challenges around our next generation cartridges and readers, and to calibrate our own quality control technologies.”
Tim Dwyer, Research and Development Director at AgPlus Diagnostics

 

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