Ultrasonic-Assisted Preparation, Characterization, and Use of Novel Biocompatible Core/Shell Fe(3)O(4)@GA@Isinglass in the Synthesis of 1,4-Dihydropyridine and 4H-Pyran Derivatives

[Image: see text] This work focussed on the synthesis of a new catalytic material isinglass (IG)-based Fe(3)O(4)@GA@IG core/shell magnetic nanoparticles and the investigation of its catalytic activity in two important multicomponent reactions. Fe(3)O(4) nanoparticles were prepared using a simple coprecipitation method and then coated with IG consisting predominantly of the protein collagen in the presence of glutaraldehyde as a cross-linking agent. The obtained hybrid material has been characterized by Fourier transform infrared analysis, scanning electron microscopy, transmission electron microscopy (TEM), vibrating sample magnetometry, energy-dispersive X-ray, X-ray diffraction (XRD), and Brunauer–Emmett–Teller analyses. The results of XRD analysis implied that the prepared nanocomposite consists of two compounds of crystalline magnetite and amorphous IG, and the formation of its core/shell structure had been confirmed by TEM images. The catalytic performance of the as-prepared core/shell bionanocatalyst was evaluated for the first time in the synthesis of 1,4-dihydropyridine and 4H-pyran derivatives under sonication in ethanol. This core/shell structure because of the superparamagnetic property of Fe(3)O(4) and unique properties of IG as a bifunctional biocatalyst offers a high potential for many catalytic applications. Recycling study revealed that no significant decrease in the catalytic activity was observed even after six runs.