The sensor can, based on a novel polymer, can measure the amount of metabolites such lactate or glucose present in a sample. These metabolites are present in sweat, tears, saliva or blood and are used as diagnostic indicators.
The sensor, developed by researchers from the University of Cambridge and King Abdullah University of Science and Technology (KAUST) in Saudi Arabia, is simpler than existing sensors and lower cost and therefore opens up range of possible health monitoring possibilities.
The team was led by Anna Maria Pappa and the work reported in a paper – ‘Direct metabolite detection with an n-type accumulation mode organic electrochemical transistor’ that appeared in Science Advances. The polymer used was one recently developed at Imperial College, London, that directly accepts electrons produced during oxidation reactions. When the material comes into contact with a liquid such as sweat, tears or blood, it absorbs ions and swells.
“In our work, we’ve overcome many of the limitations of conventional electrochemical biosensors that incorporate enzymes as the sensing material,” said Pappa, a postdoctoral researcher in Cambridge’s Department of Chemical Engineering and Biotechnology, in statement. “In conventional biosensors, the communication between the sensor’s electrode and the sensing material is not very efficient, so it’s been necessary to add molecular wires to facilitate and boost the signal.”
Initial tests of the sensors were used to measure levels of lactate, which is useful in fitness applications or to monitor patients following surgery. However, according to the researchers, the sensor can be easily modified to detect other metabolites, such as glucose or cholesterol by incorporating the appropriate enzyme, and the concentration range that the sensor can detect can be adjusted by changing the device’s geometry.
Next: First time
“This is the first time that it’s been possible to use an electron accepting polymer that can be tailored to improve communication with the enzymes, which allows for the direct detection of a metabolite: this hasn’t been straightforward until now,” said Pappa. Since the sensor does not consist of metals such as gold or platinum, it can be manufactured at a lower cost and can be easily incorporated in flexible and stretchable substrates, enabling their implementation in wearable or implantable sensing applications.
“An implantable device could allow us to monitor the metabolic activity of the brain in real time under stress conditions, such as during or immediately before a seizure and could be used to predict seizures or to assess treatment,” said Pappa.
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