Imperial team develops new biosensor material

Biological signals such as brainwaves and heartbeats are measured using organic electrochemical transistors (OECTs). Signals are carried either by electrons or their positively charged counterparts, known as holes. Materials that use primarily hole-driven transport are called 'p-type' materials, while those that use primarily electron-driven transport are known as 'n-type'.

Ambipolar materials can transport both electrons and holes, but so far nobody has been able to develop such a material for use in the body, as materials with n-type capability tend to break down in water-based environments. Imperial’s work, published in Nature Communications, describes what the team claims is the first ambipolar OECT that can conduct electrons as well as holes with high stability in water-based solutions.

"Proving that an n-type organic electrochemical transistor can operate in water paves the way for new sensor electronics with improved sensitivity,” said lead author Alexander Giovannitti, a PhD student at Imperial’s Department of Chemistry and Centre for Plastic Electronics.