Towards implantable diamond biosensors

The field of implantable biosensors is progressing at a cracking pace, for good reasons. Continuously monitoring the bodies of patients allows them to receive the best possible treatments. Doing so outside the hospital environment offers the best quality of life (and significantly reduces treatment costs). These projects explore a big challenge: how to functionalise a biocompatible surface so that it is selective, sensitive, stable and long-lived.  Diamond is highly stable and biocompatible, but as an emerging electronic material, much remains to be known about crafting working devices.

Mesoscale electronic circuits in diamond. The diamond surface can be made conductive by adsorbing hydrogen. We use an Atomic Force Microscope to 'draw' electrical pathways and devices in areas less than the width of a hair.

Laser-induced conductivity of functionalised diamond surfaces. An implantable biosensor should have no wires breaking the skin. But how then to get power in and information out? The student will investigate how pulsed lasers can be used to interface with the biosensor through the skin.

Bio-activation of diamond surfaces. The diamond is famously chemically inert, the key to its biocompatibility. Amine and carboxyl chemistry can be used to attach and interact with biological molecules, for example antigens and proteins.

Osmotic gradients in chicken eyes. Putting an electronic device in the body is complicated by the electrochemical environment. We can understand this by analysing how changes in ionic balance affect chicken eyes, which offer a useful platform for testing prototype biosensors.