According to the notice:
The Editor-in-Chief of Langmuir, in consultation and agreement with one of the authors of the article, retracts the article “Development of Fe/Fe3O4 Core-Shell Nanocubes as a Promising Magnetic Resonance Imaging Contrast Agent” on the basis of reproducibility of the TEM image in Figure 1b of the article. The decision to retract the article as made after failure to obtain convincing raw data and images associated with Figure 1b from the authors of the article and following consultation with independent experts in electron microscopy. The questions about Figure 1 also raise questions about the conclusions within the paper.
Lyudmila Bronstein was the only one of the paper’s five authors to respond to our emails. According to her:
I agree with the Editor’s decision, this is the only thing I can say. Better talk to the journal editor.
Journal editor David Whitten cited confidentiality:
Unfortunately I am not at liberty to provide more information concerning the circumstances around the retraction due to my responsibility for editorial confidentiality.
Here’s the abstract:
Here, we report the synthesis, characterization, and properties of Fe/Fe3O4 core–shell nanocubes prepared via a simple route. It includes NaBH4 reduction of FeCl3 in an ethylene glycol solution in the presence of 2-mercaptopropionic acid (surfactant) and trisodium citrate (cosurfactant) followed by surface oxidation with trimethylamine N-oxide. The morphology and structure of Fe/Fe3O4 core–shell nanocubes were characterized using transmission electron microscopy (TEM), high-resolution TEM, selected area electron diffraction, X-ray powder diffraction, and X-ray photoelectron spectroscopy. All of the methods confirm a Fe/Fe3O4core–shell structure of nanocubes. Magnetic measurements revealed that the Fe/Fe3O4core/shell nanocubes are superparamagnetic at 300 K with a saturation magnetization of 129 emu/g. The T2 weighted imaging and the T2 relaxation time showed high MRI contrast and sensitivity, making these nanocubes viable candidates as enhanced MRI contrast agents.
The paper has been cited twice, according to Google Scholar.
Hat tip: Rolf Degen