Construction of layer-by-layer self-assembly coatings based on hemicyanine derivative for photodynamic antimicrobial application

•Two-component composite films containing cationic hemicyanine and indigo carmine were prepared.•The donor-receptor structure promotes to boost the generation of ROS for antibacterial therapy.•3-layer film could kill approximate 3.6 × 108 of Ampr E. coli cells per cm2.