Fiber Optic Chemical Sensor

Our innovative fiber optic chemical sensor has an ion‑selective membrane that detects the concentration of a given ion based on its absorption spectrum.

The membrane acts as an optical cladding for the multimodal fiber that guides the signal. The technology is unique in that it detects the concentration of ions in a solution using evanescent wave spectroscopy. This makes it possible to measure the concentration of a given ion in colored and even opaque solutions, since the light propagated in the core only interrogates the membrane and never “sees” the medium under testing. Plus, users can adjust the composition of the membrane to detect different ions.

Our patented technology allows users to optically interrogate  solutions, measure ion concentrations using spectral analysis, and customize membrane composition to prolong the life of the sensor and adjust its pH range and ion sensitivity.

Our fiber optic chemical sensor also offers the following advantages:

  • Insensitive to electromagnetic interference
  • Can make measurements in opaque solutions
  • Rapid response time
  • Low-cost disposable probe, no recalibration required
  • Can be used for multi-ion or multi-site detection

With our in‑depth knowledge of chemical membrane spectroscopy and our vast experience in designing and developing optic systems, we’re able to tailor the platform to the specific application, including:

  • Water quality monitoring
  • Industrial process monitoring
  • Clinical labs
  • Agrifood
  • Pulp and paper
  • Chemically or physically aggressive media

The actual membrane is composed of a plasticized PVC lipophilic matrix that holds a pH sensitive dye, some ionic sites, and an ionophore selective to a specific ion. The membrane is thus selective to the target ion present in an aqueous solution. When bound to the target ion, the ionophore causes the dye to release a proton, which changes the dye’s absorption spectrum. This spectral change is then measured and correlated to the target ion concentration. The sensitivity of the membrane can be adjusted for different applications without altering its basic composition. Several ion‑selective membranes have already been developed (Na+, Ca2+); the ion-selective fiber (ISF) platform is compatible with multi-ion detection.

Our ion-selective fiber technology is available for technology transfer. Contact us to learn more!


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