Sustainable fluorescent dye-faujasite zeolite systems as tools for cancer bioimaging

The use of fluorescent nanoparticles for biological and medical applications has attracted great attention due to their several advantages compared to conventional fluorescent dyes. However, there is also a need for sustainable and versatile alternatives, alongside the streamlining of complex synthesis or preparations. In this work, we study the potential of the faujasite zeolite structure to encapsulate dye molecules and be applied as a bioimaging agent for cancer cells. The commercial zeolites NaY, USY, and NaX were used to encapsulate Rhodamine B (RhB) or Fluorescein (F) dyes, which present a similar tetracycle core structure. Different characterization techniques confirmed the encapsulation of the dyes and their stability. The photophysical characterization of the encapsulated RhB and F dyes was also elucidated by UV–visible and fluorescence spectroscopy. Biocompatibility was tested in different cancer cell lines and confocal laser scanning electron microscopy (CLSM) was used to track the fluorescent dye-containing zeolites. Remarkably, the dye-containing zeolite RhB@USY showed interesting multiluminescent labeling properties that make it a suitable agent for bioimaging applications. The economic feasibility of the developed fluorescent dye-zeolite probes was also examined through a detailed cost analysis, which further highlights their commercial potential.