Synthesis of a hybrid nanomaterial combining silver nanoparticles with water-soluble zinc phthalocyanines [ZnPc(CO2H)4(COATP)4@AgNPs]

Phthalocyanine based hybrid nanomaterials show promises in biomedical applications. However, their lack of solubility in aqueous phase limits their development. This paper aims at bringing some answers to this problem, by reporting the synthesis of a hybrid nanomaterial consisting of new zinc phthalocyanines substituted with four carboxylic acid functions and four thiol functions, [ZnPc(CO2H)4(COATP)4@AgNPs], associated with silver nanoparticles (AgNPs). The isolated hybrid species were characterized by UV-Visible, infrared (IR) and Raman spectroscopy, inductively coupled plasma atomic emission spectrometry (ICP-AES), powder X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS) and transmission electron microscopy (TEM). They show that the hybrid species consists in circa 20 nm large AgNPs with a characteristic absorption band that undergoes a bathochromic effect of about 30 nm in comparison to the parent AgNPs, in agreement with a functionalization of their surface. The XPS results give tangible proof of the establishment of an Ag-S bond, indicative of the coordination of the zinc phthalocyanine complexes to the AgNP surface via their peripheral thiol functions. With their four peripheral carboxylic acid functions, the zinc phthalocyanine complexes grafted on the AgNPs should impart a significant solubility to the hybrid system thus allowing its use in the biomedical field. Bull. Chem. Soc. Ethiop. 2025, 39(4), 713-729. DOI: https://dx.doi.org/10.4314/bcse.v39i4.9