Chitosan‐Silicon Phthalocyanine Conjugate as Effective Photo‐Functional Hydrogel for Tracking and Killing of Bacteria

Abstract

Hydrogels are attractive materials for many biomedical applications, including drug delivery and wound healing. A light‐triggered antibacterial activity can be conferred to the material with the introduction of appropriate photosensitizers (PS). In this study, we have synthesized water‐soluble silicon(IV)phthalocyanine derivative (SiPc) that contains four carboxylic groups on the periphery of the macrocycle. Obtained PS serves not only as an active chromophore but also as a cross‐linking gelator, enabling simple and easy synthesis of chitosan conjugate (SiPcCh). Although UV/Vis and fluorescence spectroscopic methods showed that both free and conjugated PS are non‐aggregated in water media, only SiPcCh possess remarkable antibacterial effect against Gram‐positive B. subtilis and Gram‐negative E. coli.