Optical sensor to detect vitamin B12 deficiency

University of Adelaide researchers have developed what is claimed to be a world-first optical sensor that can detect vitamin B12 in diluted human blood. The sensor’s development marks the first demonstration of vitamin B12 being measured in human blood serum without the need for a full laboratory test.

Presented at the inaugural SPIE BioPhotonics Australasia conference, the sensor uses an optical measuring technique called Raman spectroscopy, which produces a unique optical fingerprint of a target molecule — in this case, vitamin B12. The measurement takes less than a minute and requires minimal preparation.

Researchers believe the sensor could lead to the development of a low-cost, portable, broad-scale test for vitamin B12 deficiency. Dr Georgios Tsiminis, a research fellow at the University of Adelaide, noted, “Vitamin B12 deficiency has been shown to be a potential modifiable risk factor for dementia and Alzheimer’s disease and is associated with cognitive decline.”

Dr Tsiminis said the sensor could thus work as “an early first step towards a point-of-care solution for measuring and tracking B12 in healthy ageing adults. This would allow doctors to monitor B12 levels and intervene as soon as B12 deficiency was detected.”

This would provide a stark contrast to current methods, he added, in which “time and cost limitations currently mean that regular and frequent B12 measurements are not being carried out”. It would also enable tracking in high-risk patients and early intervention, topping up vitamin B12 levels when low.

“Having such a device could make this testing routine, potentially having a real impact on dementia and Alzheimer’s disease,” Dr Tsiminis said.

While the sensor cannot yet aid in diagnosing B12 deficiency in a general practice setting, Dr Tsiminis said its use “is the first time a rapid technique based on optical spectroscopy has been shown to be able to detect vitamin B12 in human blood serum. We believe this is a very promising first step towards achieving this goal.

“Our method provides a realistic basis for a system that is portable, cost-effective and affords rapid results, along the lines of the pin-prick test for diabetes,” he said.