Brother's kidney problems led to student's biosensor for detecting disease

Cape Town – Cape Peninsula University of Technology (CPUT) student Takunda Gwanzura was curious whether he could replicate his success in creating an organic solar cell for his BTech in Chemistry.

So, for his Master's of Applied Science in Chemistry he went into a completely different direction, creating a biosensor for detecting kidney disease.

He hit upon the idea of creating a test similar to a home pregnancy test, using urine or saliva.

“The whole point of a biosensor is to make something that is cheap, efficient and reliable. The pregnancy test has been one of the most successful biosensors to ever enter the market because it fulfils those three qualities.

“I wanted to prove to myself that I have the ability to replicate novelty and innovation, that it didn’t just happen serendipitously,” said Gwanzura.

The 25-year-old started working towards his Master's in Chemistry in 2016 and this week graduated summa cum laude with the thesis “Fabrication of a gold nano-rod metal-organic framework biosensor for kidney disease”.

When he was coming up with the project focus, he pointed out to his supervisor, Professor Mangaka Matoetoe, that he wanted to do something useful that could aid society. 

This was as an Ebola outbreak in West Africa was dominating headlines and he read about a scientist creating a biosensor for screening for the disease.

Around this time he got the news that his own brother was experiencing kidney problems, and his research showed him that many people realise they have a problem only when they are already in need of dialysis and/or a new kidney.

A person with a kidney disease will experience a dip in the naturally occurring protein epidermal growth factor, which makes it a good biomarker to target. Gwanzura needed a way to sense a decrease in the protein.

“People normally have between 60 and 80 nanomolar (nM) concentration but when anything starts happening to the kidney, the concentration starts to decrease. People at stage five who need dialysis have as low as 2nM concentration.”

His supervisor suggested using nanoparticles, and trial and error led him to settling on gold nanoparticles.

“Our signal is a colour change, so we don’t bother people with figures of concentration.”

The gold nanoparticles are on an electrode which is placed inside a metal-organic framework, and Gwanzura has created a working prototype.

Next, they would have to do clinical trials to test the efficacy of the Chronic Kidney Disease Biosensor. 

“Yes, I have to work on the name. My vision when I started was to synergise with CPUT expertise, so maybe I need to speak to some of the marketing people.”