4-(2-naphthalene)porphyrins are primarily used in photodynamic therapy (PDT) due to their strong absorption of light in the visible to near-infrared range and their ability to generate reactive oxygen species when exposed to light. These properties make them effective photosensitizers for targeting and destroying cancer cells.

They are also applied in organic electronics, particularly in the development of dye-sensitized solar cells (DSSCs), where they act as light-harvesting materials to improve energy conversion efficiency. Their extended π-conjugated system enhances electron delocalization and promotes efficient charge transfer.

Additionally, these compounds serve as fluorescence probes in biochemical imaging and sensing applications, benefiting from their high photostability and tunable emission characteristics. Their structural versatility allows functionalization for specific targeting in diagnostic systems.