Analytical Sciences

Abstract − Analytical Sciences, 27(11), 1121 (2011).

Determination of Dissolved Oxygen in Water Based on Its Quenching Effect on the Fluorescent Intensity of Bis(2,2′-bipyridine)-5-amino-1,10-phenanthroline Ruthenium Complex
Liqiang HU,* Chenggang NIU,*,** Guangming ZENG,* Xiaoyu WANG,* and Dawei HUANG*
*College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Ministry of Education, Hunan University, Changsha 410082, China
**State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
A water-soluble fluorescence dye, bis(2,2′-bipyridine)-5-amino-1,10-phenanthroline ruthenium complex (Ru(bpy)2(5-NH2-1,10-phen)), was synthesized and used as a fluorescence probe for detecting dissolved oxygen in water. The fluorescence intensity of the probe in different dissolved-oxygen concentrations was investigated. The sensitivity of the probe was evaluated in terms of the ratio IN2/IO2, where IN2 and IO2 correspond to the detected fluorescence intensity of nitrogen and oxygen-saturated solutions, respectively. The experimental results showed that the probe yielded a linear Stern–Volmer plot, and had a IN2/IO2 ratio of about 5.2. The detection limit, defined as three-times the standard deviation, was 8.6 × 10−7 mol L−1 after eleven determinations of nitrogen-saturated blank solutions. Additionally, the probe was pH-insensitive and ionic strength-independent with good characteristics of practicality and selectivity.