Towards a core–shell composite structure loaded with a Ru-based sensing probe and its improved site-specific oxygen sensing performance

•A site-specific core–shell composite structure was constructed for O2 sensing.•A diamine ligand with large conjugation plane was incorporated into sensing probe.•Sensing performance was improved by increasing sensing collision probability.•Sensitivity was determined as high as 12.3 with response time of 8 s.•Good stability and, more importantly, linear response, were confirmed.

The following paper was devoted to a site-specific core–shell composite structure loaded with a Ru-based sensing probe, using Fe3O4 particles as core and silica molecular sieve MCM-41 as shell, respectively. A diamine ligand with large conjugation plane was incorporated into this sensing probe, hoping to increase electronic distribution and decay lifetime of excited electrons for sensing collision, which consequently improved sensing performance. This hybrid structure was discussed and confirmed by means of electron microscope images, XRD patterns, IR spectra, N2 adsorption/desorption and thermal analysis. Photophysical analysis on this composite sample confirmed that its emission was quenchable by O2 molecules following a dynamic sensing mechanism. In virtue of this modified sensing probe with large conjugation planes, sensitivity was determined as high as 12.3 with response time of 8 s which were found superior to literature values. Good stability and, more importantly, linear response, were confirmed owing to the covalent immobilization between sensing probe and supporting host.

Graphical abstractThe following paper was devoted to a site-specific core–shell composite structure loaded with a Ru-based sensing probe, using Fe3O4 particles as core and silica molecular sieve MCM-41 as shell, respectively. In virtue of this modified sensing probe with large conjugation planes, sensitivity was determined as high as 12.3 with response time of 8 s, good stability and, more importantly, linear response.Figure optionsDownload full-size imageDownload as PowerPoint slide