Supramolecular and base-induced singlet oxygen generation enhancement of a water-soluble phthalocyanine

Investigation into the reactive oxygen species (ROS) generating abilities of photosensitizers outside of in-vitro/vivo conditions is a crucial element in the wider study of photodynamic therapy (PDT) in clinical settings. Zinc(II) phthalocyanine tetrasulfonic acid (ZnPcTS) is a water-soluble photose...

Descripción completa

Detalles Bibliográficos
Autores: Smith, Shaun M., Abelha, Thais F., Limón, David, Samperi, Mario, Sharma, Bunty, Plaetzer, Kristjan, Dumoulin, Fabienne, Amabilino, David B., Pérez García, Lluïsa
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2023
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/341119
Acceso en línea:http://hdl.handle.net/10261/341119
https://api.elsevier.com/content/abstract/scopus_id/85149250578
Access Level:acceso abierto
Palabra clave:Aggregation
Fluorescence
Hydrogel
Metal phthalocyanine
Singlet oxygen
Supramolecular
Descripción
Sumario:Investigation into the reactive oxygen species (ROS) generating abilities of photosensitizers outside of in-vitro/vivo conditions is a crucial element in the wider study of photodynamic therapy (PDT) in clinical settings. Zinc(II) phthalocyanine tetrasulfonic acid (ZnPcTS) is a water-soluble photosensitizer that can generate ROS as singlet oxygen (SO) under irradiation in the red and far-red region of the electromagnetic spectrum. The incorporation of ZnPcTS into nano-fibers of a bis-imidazolium hydrogel was demonstrated and the material was characterized with photophysical, rheological, and microscopy techniques. This supramolecular material containing ZnPcTS (named ZnPcTS_nEqBase@Gels) was found to significantly enhance the SO generation rate with respect to that of ZnPcTS in an aqueous solution. The effect is attributed mainly to reduced aggregation within the gel microenvironment compared with a solution. Furthermore, the preparation of ZnPcTS_nEqBase@Gels was carried out in the presence of varying amounts (0, 1, 2, 3, 4 eq.) of NaOH to improve the dissolution of ZnPcTSby ensuring full deprotonation of the sulfonate. The gel material containing 4 equivalents of NaOH per phthalocyanine was found to have a significantly greater SO-generating ability than the corresponding material containing no base. This phenomenon was shown to be partially a consequence of reduced aggregation as observed in the spectroscopic characterization. The enhancement in SO generation induced by this type of hybrid material makes it an attractive candidate to be used in different applications when efficient SO production is required.