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

Jingshuai Li,Du Bin,Zhankui Guo,Bing Wang,Hongmin Ma,Qi Wang,Yong Zhang,Qin Wei

doi:10.1038/srep23558

Abstract

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 Fe3+. The proposed nanoprobe shows excellent fluorescent property and high selectivity for Fe3+ due to the binding affinity of L-Cys with Fe3+. The binding of Fe3+ to the nanoprobe induces an apparent decrease of the fluorescence. Thus a highly selective fluorescent chemosensor for Fe3+ was proposed based on Fe3O4@ZnO nanoprobe. The magnetism of the nanoprobe enables the facile separation of bound Fe3+ 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 Fe3+ 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.

Highlights

The development of highly sensitive fluorescent probes for the selective detection of heavy metal ions and transition metals has been inspiring the scientific community in the past few years as a result of concern for human health and environmental safety[1,2,3,4,5]
All other reagents used in this study were analytical grade, and ultrapure water was used in the preparation of all solutions
The morphology of Fe3O4 and Fe3O4@ZnO was observed by Transmission electron microscope (TEM)

Summary

Introduction

The development of highly sensitive fluorescent probes for the selective detection of heavy metal ions and transition metals has been inspiring the scientific community in the past few years as a result of concern for human health and environmental safety[1,2,3,4,5]. The results showed that Fe3O4@ZnO@L-Cys quantificationally detected Fe3+ with high sensitivity and selectivity under a pH range (pH 4.98–7.39) and could remove Fe3+ from the water sample. To test the influence of ionic strength on the fluorescence of Fe3O4@ZnO@L-Cys before and after the addition of Fe3+, a series of Fe3O4@ZnO@L-Cys solutions containing different concentrations of NaCl (0.33, 0.99, 1.98, 2.97, 3.96 and 4.95 mmol L−1) was prepared and the emission spectra was measured.

Results

Conclusion