In situ 3D bacterial cellulose/nitrogen-doped graphene oxide quantum dot-based membrane fluorescent probes for aggregation-induced detection of iron ions

The development of a bio-based fluorescent membrane sensor for iron ions is elaborated. A three-dimensional (3D) network structure of bacterial cellulose (BC) made by layer-by-layer in situ cultivation contained nitrogen doped graphene oxide quantum dots (N-GOQDs). The obtained BC/N-GOQDs were analyzed by SEM, TEM and XPS and demonstrated that the blue emissive N-GOQDs were homogeneously distributed in the BC mats through hydrogen bonding. These materials were found to be useful for the detection of iron ions in aqueous solutions. Experimental data showed the blue-emitting BC/N-GOQDs fluorescent probes exhibited a sensitive response to Fe3+ within a favorable concentration range of 0.5–650 μM with a very good lower limit detection of 69 nM at a signal-to-noise ratio of 3 (S/N = 3). Meanwhile, the BC/N-GOQDs–Fe3+ complexes has good reproducibility after treatment with EDTA. The quenching mechanism was attributed to strong coordination between surface functional groups (–NH2 and –OH) and Fe3+ which was successfully applied in real water samples. Diagram of quenching mechanism of the BC/N-GOQDs nanocomposites towards Fe3+ ions.