A nano-sensing composite platform combining magnetic and emissive features: Fabrication and performance.

• A nano-sensing platform was endowed with recycling performance. • This composite structure showed emission response for analyte nitrite ion. • Static sensing mechanism was confirmed with spectral proof and dynamic evidence. The following paper was devoted to two nitrite sensing platforms having a core-shell structure, where Fe 3 O 4 nanoparticles were used as core, a silica molecular sieve MCM-41 was constructed as shell and two rhodamine chemosensors were synthesized as probe, respectively. This magnetic core endowed these two sensing platforms with site-specific aggregation ability. They were carefully characterized through their electron microscopy images, porous analysis, magnetic performance, IR curves and thermal stability analysis. Experimental result suggested that these two sensing platforms were sensitive towards nitrite and their emission was quenchable by nitrite. A static sensing mechanism between probe and analyte through an additive reaction was established by emission decay lifetime analysis. These two sensing platforms showed limit of detection as low as 1.2 μM. Additionally, after their nitrite sensing, these two sensing platforms and their emission could be recovered by sulphamic acid, realizing recyclability. [ABSTRACT FROM AUTHOR]