Scheme 1. Schematic of the multi-functional antibacterial system (APNB) based on the ABP phage and Nile blue photosensitizer (NB) for the treatment of multi-drug resistant Acinetobacter baumannii and its biofilms. Structural modification of NB with a sulfur atom contributes the high ROS generation ability, and the bacteriophages provide specific binding to pathogenic microorganisms. The developed APNB has multiple functions, including bacteria targeting, near-infrared fluorescence imaging and combination therapy (PACT and phage therapy).