A nanoporous Cu-Ag thin film at the Cu-Ag-Zn alloy surface by spontaneous dissolution of Zn and Cu in different degrees as a highly sensitive non-enzymatic glucose sensor

• Published in: Electrochimica acta 2019-10, Vol.320, p.134599, Article 134599
• Main Authors: Liu, Sanmei, Liu, Bingwu, Gong, Chenfan, Li, Zelin
• Format: Article
• Language: English
• Subjects: Auto-dealloying; Bimetals; Copper; Copper base alloys; Cu-Ag binary metals; Dealloying; Electrochemical non-enzymatic glucose sensor; Electrodes; Glucose; Nanoparticles; Nanoporous film; Oxidation; Response time; Sensors; Silver; Substrates; Ternary alloys; Thin films; Zinc
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2019.134599

In this article, we present a new dealloying way to fabricate a stable nanoporous Cu-Ag bimetallic thin film as a glucose sensor. The nanoporous Cu-Ag thin film is obtained under a mild condition simply by immersing a Cu-Ag-Zn alloy disk electrode (with minor Ag) of 2-mm diameter in 1 M KOH solution at room temperature for a short time of 3 h. The metallic Zn and Cu at the ternary alloy surface are automatically dissolved completely and partially via oxidation reactions with the solvent H2O and the dissolved O2, respectively, leaving a nanoporous structure on the disk substrate. The method is very facile, green and cost-effective. The prepared nanoporous Cu-Ag thin film consists of small nanoparticles. The presence of lesser Ag prevents the small Cu-Ag nanoparticles from agglomeration and enhances the electro-oxidation of glucose compared with the dealloyed Cu-Zn electrode. The prepared nanoporous Cu-Ag film can serve as an advanced glucose sensor with a high sensitivity of 3572 μA mM−1 cm−2, a low detection limit of 0.37 μM, a wide linear range up to 6 mM, excellent reproducibility (RSD