Carbon tape coated with gold film as stickers for bulk fabrication of disposable gold electrodes to detect Cr(VI)

Fabrication of disposable gold working electrodes in bulk is desirable for their extensive application in electrochemical detection. In this paper the gold film electrodes were prepared by sputtering the gold film with the thickness of ∼12 nm on the double sided conductive carbon tape. The gold film coated carbon tape could be used like stickers with small square pieces and attached on ITO glass for fabrication of disposable gold film electrodes. The electrochemical responses of the gold film modified electrodes on Cr(VI) in acidic solutions were similar to previous gold electrodes, suggesting the similar mechanism as before. Cr(VI) could be determined by the amperometric method with the detection limit of 0.7 μg L−1 (0.013 μM), which was significantly improved compared with previously reported disposable gold-based electrodes. The batch-by-batch (n = 20) reproducibility of the fabricated electrodes was 7.3% at 50 μg L−1 and 3.8% at 5.0 mg L−1, respectively. The disposable electrodes could be applied to quantify Cr(VI) in real samples including plastics, tap water and lake water with results in agreement with those obtained with HPLC-ICP-MS. This study provides a simple and effective alternative for preparation of disposable gold film electrodes.