Scientists are working to mass-produce the 'holy grail' of blood sugar testing to make it easier for diabetics to check their blood sugar levels.

The researchers, at the University of Newcastle in Australia, have created a non-invasive, convenient and pain-free strip that checks glucose levels in the saliva.

If rolled out, the strip would mean people with diabetes would no longer have to prick their finger to draw blood during their daily checks.

They could just place the strip on their tongue, wait a few minutes and then see the results on a smartphone app.

The project has secured AU$6.3 million (£3.4 million) in funding from the Australian government to establish a facility to mass-produce the test kits should clinical trials be passed.

Construction of the facility will begin this year, with the first devices due to roll off the production line by 2023.

Individual testing strips could then be purchased in bulk in pharmacies for only about a penny each.

The project has been led by Paul Dastoor, a professor of physics at the University of Newcastle in New South Wales.

Professor Dastoor was inspired by his wife, a primary school teacher who has helped young children to monitor their blood glucose levels.

'It's a heartbreaking scenario when the lunch bell rings and everyone runs to the playground, bar an unfortunate few who stay back to surrender their finger for blood testing at every meal time,' he said.

'Our vision was to create a world where no one needs to bleed in order to eat.

'[This test] really does open up the prospect of pain-free, low-cost glucose testing and hopefully much better outcomes for diabetes sufferers.

'The exciting prospect is that in the future we might have a test for diabetes that doesn't involve stabbing yourself four to six times a day.'

Glucose in saliva exists in minute concentrations, so an 'incredibly powerful platform' is needed to detect it.

'Saliva also contains a plethora of other substances, so you've then got to tune out a lot of 'noise' to ensure results are accurate,' Professor Dastoor said.

The strip is a biosensor, meaning it measures biological or chemical reactions by generating signals.

It's similar in size to a stick of chewing gum, but considerably thinner.

The strip consists of a very thin transistor that contains an enzyme called glucose oxidase.

When placed on the tongue, the glucose oxidase reacts with glucose in the saliva to form hydrogen peroxide.

This hydrogen peroxide is then 'decomposed' into hydrogen ions that generate an electrical signal, which can be picked up, processed and displayed by a smartphone app.

Amazingly, the electronic materials in the transistor are inks, meaning the test could be made through printing at a low cost.

The paint, or ink, used in the tests has semiconducting particles, so electronic designs can be downloaded and printed from an inkjet printer.

'Imagine being able to have your own ink at home, allowing you to print your own glucose test,' Professor Dastoor said.

According to Professor Dastoor, the technology could also be transferred to Covid-19 testing and allergen, hormone and cancer testing.

The university is already working with Harvard University on a test for Covid-19 using the same technology.

'The holy grail of glucose testing has been something that is non-invasive,' he said.

'I think its going to radically change the way we think about medical devices and in particular sensors because we can print these at remarkably low cost.'

Diabetes is predicted to become the most common disease in Australia by 2023, ahead of cancer and heart disease.

Globally, the condition affects more than 460 million adults across the world, and is the seventh leading cause of disability.

It accounts for more than $320 billion (£250 million) in health care costs in the US alone.

More than four million people in the UK have diabetes, with 90 per cent of these cases classified as type 2. The figure is set to rise to 5 million by 2025 because of the obesity epidemic.