Investigation of a robust flow-through Cu(I) optical sensor using 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline immobilized into a Nafion film

A robust optical sensor for detection of Cu(I) in water and using fiber optic interrogation is demonstrated. The reagent bathocuproine (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline or BCP) is immobilized into a film of Nafion and the absorbance changes associated with the formation of a Cu(I)-BCP complex are used to detect and quantify Cu(I) in water. The response of the sensor is determined for varying concentrations of Cu(I) in water. Two different measurement techniques are investigated. In the recycled technique the Cu(I)-BCP complex is eluted with 0.1 M nitric acid after each measurement, whereas in the continuous technique the sensor is exposed to consecutively larger concentrations of Cu(I). Detection of ppb levels of Cu(I) is demonstrated and calibration curves for both techniques are constructed. (C) 1998 Elsevier Science S.A. All rights reserved.