Paper-based device with a sputtered tin-film electrode for the voltammetric determination of Cd(II) and Zn(II)

Publication date: 1 May 2018
Source:Sensors and Actuators B: Chemical, Volume 260
Author(s): Christos Kokkinos, Anastasios Economou, Dimosthenis Giokas
This work describes a microfabricated electrochemical paper-based analytical device (ePAD) for the simultaneous voltammetric determination of Cd(II) and Zn(II) at trace levels. The ePAD integrates a wax-printed microfluidic channel and, on the reverse side of the paper, sputtered thin films of Sn, Pt and Ag serving as the working, counter and reference electrodes, respectively. The microfluidic channel ensures electrolytic contact between the electrodes with only 10 μL of working solution. The determination of Cd(II) and Zn(II) is performed at the 400 nm-thick sputtered Sn-film working electrode, in a pump-free and unstirred mode, by anodic stripping voltammetry. Under the selected conditions, the limits of detection were 0.9 μg L⁻¹ Cd(II) and 1.1 μg L⁻¹ Zn(II) and the between-sensor reproducibility was 5.7% for Cd(II) and 7.5% for Zn(II) at the 30 μg L⁻¹ level (n = 5). The ePAD costs only 0.11$ and presents favorable fabrication and operational features, that make it suitable for simple, fast and on-site analysis.

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