Metal-Organic Framework-Based Fiber Optic Sensor for Chromium(VI) Detection.

This study demonstrates a novel fiber optic sensing strategy for selective adsorption and rapid detection of Cr(VI) ions by exploiting a suitable metal-organic framework matrix and the characteristic spectral absorption of Cr(VI) at 395 nm wavelength, respectively. U-bent fiber optic sensor (U-FOS) probes that exhibit remarkably high evanescent wave-based absorbance sensitivity were employed to efficiently detect the Cr(VI) ions that are adsorbed to a stable zeolitic imidazolate framework (ZIF-67) matrix immobilized on the probe surface. A facile technique was developed for the fabrication of ZIF-67-coated U-FOS probes (FOS/ZIF-67) involving an deposition process followed by heat treatment.