Lanthanum loaded graphitic carbon nitride nanosheets for highly sensitive and selective fluorescent detection of iron ions

A facile synthesis of lanthanum (La) loaded graphitic carbon nitride nanosheets (CNNS) was developed in this study. The obtained La-CNNS exhibited an intense emission peak at 255   nm, owing to fluorescence enhancement effect of introduced La on the surface of CNNS. La-CNNS showed excitation-independent behavior and blue shift compared with CNNS. It displayed great fluorescence quenching via photoinduced electron transfer (PET) when a small amount of Fe 3+ was added. The probe exhibited a wide linear response concentration range (0.1–20   μM) to Fe 3+ with a detection limit of 0.0232   μM. The La-CNNS fluorescence probe was highly selective and suitable for Fe 3+ analysis in natural water samples.