The present technology provides a system for monitoring quorum-sensing in bacteria comprising bacteria that release at least one membrane-lytic toxin when the bacteria are at a quorum-sensing density; synthetic lipid vesicles comprising an environmentally sensitive indicator, wherein the synthetic lipid vesicles release the environmentally sensitive dye in the presence of an effective amount of the membrane-lytic toxins; and a growth medium; wherein the bacteria and synthetic lipid vesicles are in contact with the growth medium. Methods using the system and compounds discovered with the system (e.g., compounds of Formulas I and II) are also disclosed.