Enhanced visible light response of a WO3 photoelectrode with an immobilized fibrous gold nanoparticle assembly using an amyloid-β peptide

Abstract

A WO₃ photoelectrode immobilizing a fibrous gold nanoparticle (AuNP) assembly using an amyloid-β (Aβ) peptide was constructed and its ability for photocurrent generation upon visible light irradiation was investigated. AuNPs attached using Aβ peptide (Aβ-AuNP) assemble with a fibrous structure at pH 4.5, which disperses at pH 11. The modified Aβ-AuNPs are immobilized on the surface of WO₃ fabricated on a fluorine-doped tin oxide (FTO) electrode (Aβ-AuNP_ass@WO₃/FTO or Aβ-AuNP_dis@WO₃/FTO, respectively). The photocurrent generation response of the Aβ-AuNP_ass@WO₃/FTO electrode is clearly increased relative to that of Aβ-AuNP_dis@WO₃/FTO upon visible light irradiation (λ = 420–750 nm), indicating that the fibrous AuNP assembly enhances the visible light response of the WO₃ photoelectrode.