Preparation and properties of fiber optic oxygen sensing material by thermo-polymerization method

A new kind of fiber optic oxygen sensing material based on the fluorescence quenching of Ru(bpy)(3)Cl-2 was prepared by the therno-polymerization method. The ruthenium dye was immobilized in N, N-methylene bisacrylamide(MBBA) polymer by physically trapping while MBBA was covalently crosslinked on the glass micro-beads by NaHSO3-O-2-MnSO4 initiator system. The lock-in amplifyication technology was used for the detection of their sensing properties. The influences of indicator concentration, glass microbeads diameter, post polymerization time, concentration and reaction time of glutaraldehyde on the properties of sensing materials were studied. To optimize the influencing factors to the sensing materials, the indicator concentration of 0.7 g/L, glass micro-beads diameter of 0.3 mm, post polymerization time of 5 h were achieved. The immobilization stability of ruthenium dye and the performance of the sensing materials were improved by the new polymerization system. An absolute detection limit of 3 x 10-6 (V/V) and the response time of 10 s were obtained. This kind of sensing materials has good stability and their life time is 2 years.