Development of an oxidase-based glucose sensor using thickness-shear-mode quartz crystals

A glucose biosensor has been developed which combines the substrate specificity offered by the enzyme glucose oxidase with the high sensitivity of a quartz crystal thickness-shear-mode sensor. Glucose is detected via the enzyme-catalysed formation of insoluble films of oxidised o-dianisidine on the crystal surface. Glucose levels can be measured in situ and the sensor has a fast response time of 80–100 s with a linear response to glucose in the concentration range 30–200 μM. Sensor sensitivity is of the order 4 Ω μM−1 glucose. The crystal is readily regenerated between assays.