Synthesis of chitosan grafted with aminomethyl zinc phthalocyanine for photodynamic therapy

Abstract

This paper reports the synthesis of a substituted aminomethyl zinc phthalocyanine (AmPcZn) and its covalent grafting onto chitosan via an ethyl chloroformate-mediated reaction. Chitosan-based copolymers containing 10%, 20%, 30%, and 60% (w/w) AmPcZn were successfully obtained. The chemical structure of the synthesized AmPcZn was confirmed by 1H-NMR spectroscopy and elemental analysis, which were consistent with the expected molecular composition. The grafting reaction and structural integrity of the resulting copolymers were investigated using Fourier-transform infrared (FTIR) and UV-Vis spectroscopies. FTIR spectra revealed characteristic amide and carbonyl stretching bands, confirming covalent bond formation between chitosan and AmPcZn. UV-Vis measurements showed a concentration-dependent increase in absorbance and a typical splitting of the Q-band with band at 605 nm and 715 nm, indicating the successful incorporation of the phthalocyanine moiety into the polymeric matrix.

Keywords

• znpc derivative
• chitosan
• grafting reaction
• uv-vis spectroscopy
• ftir spectroscopy