A biosensor comprising an electrically conductive substrate coated with a modified chitosan biopolymer that has been electrodeposited on the substrate, wherein said modified chitosan biopolymer comprises at least one vesicle binding molecule. The biosensor is manufactured by a method where a modified chitosan biopolymer is electrodeposited on a substrate. The method is also used to manufacture a modified chitosan biopolymer film by electrodeposition of the chitosan on the substrate and later removing the film from the substrate after electrodeposition. The resulting film can be used in bandages to treat various types of wounds. The biosensor can also be used to detect various analytes in samples.