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

Flexible catalytic electrodes for oxidation of biomolecules were realized by a supercritical carbon dioxide (scCO 2 )-assisted functionalization process. The flexible catalytic electrode was a composite of Au/Ni-P/polyethylene terephthalate (PET). ScCO 2 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 scCO 2 . 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 scCO 2 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. • Flexible catalytic electrode is realized by supercritical CO 2 catalyzation. • The flexible catalytic electrode is a composite of Au/Ni-P/PET. • Ni-P is successfully metallized on PET film followed by gold disposition. • Catalytic activities in oxidation of glucose, ascorbic acid and urea are demonstrated.