Best bet is probably a set of raid frames like Healbot or Vuhdo configured to show an icon when that's buff is on someone just so you can monitor everyone at a glance.
Gershuun @ Borean Tundra US - Interface & Macros Moderator
You can set Grid to show when a specific buff or debuff is on a raid member. You will need to manually add the buff if it isn't on the list already. Then, you can set Grid to display an image in the middle or just a dot at one of (IIRC) 8 points around the edge of the player's square. You can even change the color of the dot so it stands out more. Healbot works in a similar fashion. I haven't used other raid frame addons, but I imagine most could do this.