Type-3 copper proteins as biocompatible and reusable oxygen sensors

Type-3 copper proteins like tyrosinase (Ty) and hemocyanin (Hc) contain a dinuclear active Cu site that binds di-oxygen reversibly. The binding can be detected by fluorescence spectroscopy. Immobilization of the proteins (Ty and Hc) in a sol-gel matrix stabilizes them and does not affect their oxygen binding capacity. This finding is an important step towards the realisation of a sensitive and robust oxygen sensor.