Trace analysis on chromium (VI) in water by pre-concentration using a superhydrophobic surface and rapid sensing using a chemical-responsive adhesive tape

Weirui Tan, Aruna, Zhonghao Xu, Liyuan Zhang, Wei Shen

Research output: Contribution to journalArticleResearchpeer-review

3 Citations (Scopus)


Heavy metal ions in water resources present great threats to human health. Chromium (Cr), as the frequently used heavy metal in industrial processes and everyday life, requires a low-cost, fast and effective means to determine its concentration, especially in drinking water. Conventional colorimetric paper-based analytical devices (PADs), due to the limited sensitivity, are unable to quantify the most harmful heavy metal ions to the drinking water standard. In this work, we present a method of using a superhydrophobic (SH) paper to concentrate Cr6+ from solutions of very low concentration to obtain the precipitated Cr6+ salt particulates. A known volume of Cr6+-containing solution was concentrated to “a spot” on the SH paper through drying, so that trace amount of Cr6+ can be quantified via the application of a specifically-designed chemical-responsive adhesive tape (CAT) sensor, loaded with Cr6+- specific indicator, on to the concentrated Cr6+ spot. The detection limit of the SH-CAT method for Cr6+ is 0.05 mg/L, which is the permitted maximum concentration in drinking water and is significantly lower than that of conventional PADs. The interference and the accuracy studies also show the reliability of this method for measuring trace amounts of analytes.

Original languageEnglish
Article number121116
Number of pages6
Publication statusPublished - 1 Oct 2020


  • Chemical-responsive adhesive tape (CAT) sensor
  • Drinking water
  • Pre-concentration
  • Superhydrophobic (SH) surface
  • Trace analysis of Cr

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