Preparation and characterization of pH-responsive metal-polyphenol structure coated nanoparticles
Qile Xia, Yan Liang, Ailing Cao, Yan Cao, Luyun Cai
Abstract
In this paper, tannic acid (TA) and Fe<sup>3+</sup> were added to form a layer of metal-polyphenol network structure on the surface of the nanoparticles which were fabricated by zein and carbon quantum dots (CQDs) encapsulating Phlorotannins (PTN). pH-responsive nanoparticles were prepared successfully (zein-PTN-CQDs-Fe<sup>Ⅲ</sup>). Further, the formation of composite nanoparticles was confirmed by a series of characterization methods. The zeta-potential and Fourier transform infrared spectroscopy data proved that electrostatic interaction and hydrogen bonding are dominant forces to form nanoparticles. The encapsulation efficiency (EE) revealed that metal-polyphenol network structure could improve the EE of PTN. Thermogravimetric analysis and differential scanning calorimetry experiment indicated the thermal stability of zein-PTN-CQDs-Fe<sup>Ⅲ</sup> nanoparticles increased because of metal-polyphenol network structure. The pH-responsive nanoparticles greatly increased the release rate of active substances and achived targeted release.