Photophysical characterization of xanthene dyes

The growing interest in using photodynamic therapy for cancer treatment and antimicrobial applications has prompted the search for different classes of dyes. In general, the protocols of these studies are different, making it difficult to compare their efficiency directly. Here, we apply a controlled protocol to analyze the photophysical properties of Erythrosin B, Eosin Y, and Rose Bengal using a set of optical techniques. The results show that Erythrosine has the best singlet oxygen generation capacity. This result, added to the well-known low toxicity of Erythrosine, makes it a good choice among the xanthenes for health applications.