Agglomerates of Silver Nanoparticles Stabilized by Hydrophobic Interaction

Abstract The process of formation of a new type of agglomerates of silver nanoparticles formed during the adsorption of albendazole has been studied. It has been shown that at the isoelectric point (pH 6.3), albendazole molecules, adsorbed on the surface of nanoparticles, induce their agglomeration with the formation of loose structures stabilized mainly by hydrophobic interaction. This process leads to the formation of “hot spots” with a local enhancement of the electromagnetic field, which is confirmed by a sharp increase in the intensity of the giant Raman scattering signal. These agglomerates have fundamental differences in structure and stability from agglomerates induced by electrostatic interaction. They exhibit high intensity giant Raman scattering, unique morphology, and pH-dependent adsorption. A comprehensive study using Raman spectroscopy, dynamic light scattering, ζ-potential measurements, scanning electron microscopy, and high-performance liquid chromatography confirmed the formation of a new type of nanostructures with controlled properties. The obtained results open up prospects for the development of highly efficient substrates for giant Raman scattering and targeted drug delivery systems.