Luminescent oxygen probes based on TbIII complexes chemically bonded to polydimethylsiloxane

• DOI: 10.1016/j.snb.2019.02.085
• Publication Date: 2019-02-21T16:54:30Z
• Authors: Rafael D.L. Gaspar; Sofia M.M. Ferraz; Pamela C. Padovani; Paula R. Fortes; Italo O. Mazali; Fernando A. Sigoli; Ivo M. Raimundo
• Keywords: Siloxane; Polydimethylsiloxane; Surface Modification; Oxygen sensor

Abstract In this work, the functionalization degree of siloxane crosslinkers by allyldiphenylphosphine oxide (adppo) and its effect on the performance of a lanthanide-based optical oxygen sensor were evaluated. Linear poly(dimethyl-co-hydromethylsiloxane) (PMS) and cyclic tetramethylcyclotetrasiloxane (D4i) crosslinkers were functionalized with different concentrations of adppo to chemically bond the [Tb(dcba)3]·1/2H2O (dcba = dichlorobenzoate) complex. Mechanically stable luminescent silicone membranes were obtained after the curing of the poly(dimethylsiloxane)-vinyl terminated siloxane backbone with the pre-functionalized crosslinkers. Sensing materials exhibit green emission upon 350 nm excitation, and their luminescent properties are dependent of functionalization degree of the crosslinkers. The luminescent sensor materials show fully reversible response and non-linear Stern-Volmer plots, which are fitted by two quenching parameter model, with highest KSV of 0.08930%−1 when using functionalized D4i as crosslinker and complex concentration of 0.75%.