Detection of low-concentration heavy metal ions using optical microfiber sensor

Heavy metal pollution in natural water environment is always a concern in both human and ecosystem health. All current systems available in the market for detecting heavy metal ions have common drawbacks such as bulky size, expensive set-up and costly maintenance. This paper presents an optical microfiber sensor functionalized with chelating agent to detect the existence of specific heavy metal ions of low concentration. To the best of our knowledge, coating of chelating agent on silica microfiber of very small diameter (3.9 μm) is the first such report. A clear spectral shift was observed when the sensor was immersed into metal ion solution of concentration 10 ppb.