Highly selective fluorescent chemosensor for detection of Fe(3+) based on Fe3O4@ZnO.

The combination of fluorescent nanoparticles and specific molecular probes appears to be a promising strategy for developing fluorescent nanoprobes. In this work, L-cysteine (L-Cys) capped Fe3O4@ZnO core-shell nanoparticles were synthesized for the highly selective detection of Fe(3+). The proposed nanoprobe shows excellent fluorescent property and high selectivity for Fe(3+) due to the binding affinity of L-Cys with Fe(3+). The binding of Fe(3+) to the nanoprobe induces an apparent decrease of the fluorescence. Thus a highly selective fluorescent chemosensor for Fe(3+) was proposed based on Fe3O4@ZnO nanoprobe. The magnetism of the nanoprobe enables the facile separation of bound Fe(3+) from the sample solution with an external magnetic field, which effectively reduces the interference of matrix. The detection limit was 3 nmol L(-1) with a rapid response time of less than 1 min. The proposed method was applied to detect Fe(3+) in both serum and wastewater samples with acceptable performance. All above features indicated that the proposed fluorescent probe as sensing platform held great potential in applications of biological and analytical field.