Nitzan and his group study the photoinactivation of Gram-positive and Gram-negative bacteria by using photosensitizer–antibiotic conjugates and liposome-encapsulated water-soluble photosensitizers. In another approach to inactivation of bacteria, conducted in collaboration with Dr. R. Cahan and Dr. M. Nisnevitch from the Ariel University Center, the group uses intracellular antimicrobial photodynamic therapy and light-activated antibacterial surfaces.