Gamelas, Sara R. D.Bartolomeu, MariaVieira, CátiaFaustino, Maria A. F.Tomé, João P. C.Tomé, Augusto C.Almeida, AdelaideLourenço, Leandro M. O.2024-09-112024-09-112023-11http://hdl.handle.net/10400.14/46474Infectious diseases remain a leading cause of death all around the world. Over the last three decades, the alarming and escalating emergence of antibiotic-resistant bacterial strains has caused some concern among the scientific community [1,2]. Photodynamic inactivation (PDI) emerges as an alternative for inactivating microorganisms, including bacteria [1–3]. The use of phthalocyanine (Pc) derivatives as photosensitizers (PS) in PDI has already proven effectiveness against various microorganisms [4]. Moreover, the addition of KI as a coadjutant can, in certain circumstances, enhance the efficiency of neutral, negative, and positively charged PS against Gram-negative and Gram-positive bacteria [2,4]. In this study will be demonstrated the effect of KI in PDI of E. coli and S. aureus with cationic Pcs bearing tris(trimethylammoniummethyl) or pyridinium-pyrazolyl groups.engconference object