A nanocomposite with core-shell structure for site-specific oxygen sensing: Synthesis, characterization, photophysical feature and sensing performance

In this paper, our effort was focused on site-specific optical sensing of O-2, using a magnetic-luminescent nanocomposite with core shell structure. Superamagnetic Fe3O4 core was designed for site-specific guiding, while a silica molecular sieve MCM-41 was constructed as shell, serving as supporting matrix. A Ru(II) complex was embedded into MCM-41 tunnels through a coupling ligand, acting as sensing probe. This composite structure was analyzed and discussed by electron microscope images, XRD analysis, IR/emission spectra, thermal degradation and N-2 adsorption/desorption. The emission of this composite was found quenchable by O-2 molecules, following a dynamic mechanism. Sensitivity of 11.6 and response time of 14s were observed from this composite with a linear Stern-Volmer working curve. Its potential material for photodynamic therapy was tentatively explored as well. (C) 2015 Elsevier B.V. All rights reserved.