A Critical Study on the Performance of MOF-808 Supported Phthalocyanine Photosensitizer

Abstract

Systems based on metal–organic frameworks (MOFs) have recently found applications in various areas from catalysis to drug delivery. MOF functionalization with guest molecules expands the capabilities of such systems by combining both components’ strengths. In this regard, embedding a photosensitizer in a framework matrix is a potentially effective way of tackling the limitations of the former while taking advantage of the latter’s unique properties. It, however, requires optimization and a careful choice of appropriate application conditions, while the limitations of porous supports are widely underreported. In this work, we bound copper(II) phthalocyanine tetrasulfonic acid (TSCuPc) to MOF-808 and utilized electron paramagnetic resonance spectroscopy using spin traps to study its photosensitizing performance in various media. By comparing its performance with that of bare TSCuPc and measuring photosensitizer release from the composite, we were able to distinguish the factors limiting photosensitization efficiency and highlight the prospects of using MOF-808-based systems in these media. Observed composite instability in the presence of phosphate ions is a crucial effect that determines the approaches to MOF-808 biomedical applications.