Supercritical carbon dioxide-assisted functionalization of polyethylene terephthalate (PET) toward flexible catalytic electrodes

Abstract

Flexible catalytic electrodes for oxidation of biomolecules were realized by a supercritical carbon dioxide (scCO2)-assisted functionalization process. The flexible catalytic electrode was a composite of Au/Ni-P/polyethylene terephthalate (PET). ScCO2 was used as the solvent in the catalyzation step of an electroless plating process. Palladium bis-hexafluoroacetylacetonate was used as the source of the palladium catalyst for the high solubility in scCO2. After the catalyzation step, Ni-P was firstly deposited on the catalyzed PET as the sacrificial layer for the later gold deposition. Electrical resistance of the Ni-P/PET composite was 0.27 Ω and maintained at 0.30 Ω after a tape adhesion test, which revealed the positive contribution of the scCO2 catalyzation on reliability of the metallized PET. After deposition of the gold layer, the flexible Au/Ni-P/PET composite was evaluated as the catalytic electrode in oxidation of urea, ascorbic acid and glucose to demonstrate the applicability in flexible biosensors.