An optical sensor for mercuric ion based on immobilization of Rhodamine B derivative in PVC membrane

A novel prepared mercuric ion PVC membrane sensor based on a Rhodamine B derivative (RND) as a selective sensing material was described. The sensor exhibited a specific fluorescent off-on response to Hg(2+), and showed a linear response over the Hg(2+) concentration range from 1.0 × 10(-9) to 2.0 × 10(-3)M with a very low detection limit of 8.1 × 10(-10)M in bulk method. The sensor has also been incorporated into a flow-cell for determination of Hg(2+) in flowing streams with improved sensitivity and detection limit. The sensor shows excellent selectivity toward Hg(2+) with respect to common coexisting cations. The proposed fluorescence optode was successfully applied to detect Hg(2+) in environmental water samples and fish.