KWRRI Research Reports


The objective of this study was the development of chromo- and fluoroionophores and their subsequent use in sensors capable of surface and groundwater monitoring. Several reagents (modified crown ethers and porphyrins) were synthesized based on principles of chemical recognition and used for metal and pH sensing. The modified crown ether reagents include a chromogenic or fluorogenic group. The selectivity of these reagents is controlled by the size of the crown ether ring and the type of the chromogenic or fluorogenic side-arm. In addition, a fluorogenic crown ether was synthesized that incorporates a fluorogenic side-arm and a perfluorinated carbon chain. The later was used to immobilize the fluoroionophore on PTFE membranes, which were placed at the tip of an optical fiber bundle. This configuration led to the development of a divalent ion-selective fiber optic sensor. Finally, cobalt(Il)tetra(p-hydroxyphenyl)porphyrin, [Co(p-OH)TPP] was electropolymerized on the surface of optically transparent electrodes to form membranes composed of the polymerized [Co(p-OH)TPP] chromoionophore. These membrane phases, capable of molecular recognition, were used for the construction of fiber optic sensors.

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Funding Information

The work upon which this report is based was supported in part by funds provided by the U.S. Department of the Interior, Washington D.C. as authorized by the Water Resources Act of 1990 (Public Law 101-397.