Abstract
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.
