Anti-fouling sol-gel-derived sensing membrane entrapped with polymer containing phosphorylcholine groups for an optical O2 sensor application

An anti-fouling hybrid material composed of sol-gel-based material and polymer containing phosphorylcholine groups (PMB) was developed and applied to an optical O2 sensor. An O2 sensing dye, tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) chloride (RuDPP) was entrapped in the sol-gel-derived matrices in order to prepare the anti-fouling O2 sensing membrane, and the effect of the entrapped PMB on the performance of the O2 sensor was studied. The anti-fouling effect was observed using scanning electron microscopy (SEM) after incubating E. coli on the sol-gel-derived sensing membrane. The efficiency of the O2 sensing membrane in the absence and presence of PMB was compared through the measurement of the fluorescence quenching rate constant of RuDPP in the sensing membrane by dissolved O2 in H2O. Reversibility was observed through changes in the fluorescence intensity upon alternate exposure of the sensing membrane to O2 and N2 gas. The prepared sol-gel-derived sensing membrane also has good stability and reproducibility. The results indicated that the anti-fouling sol-gel-derived O2 sensing membranes containing PMB were stable and the performance of the sensor was not affected at all by the entrapped PMB in the sol-gel-derived matrix.