http://throb.gizmodo.com/sorry-dont-...-so-1714706951
Getting the antibody from an infected person to bind to the antigen on the test strip is just the first step. The reaction is still invisible until you add a dye. How do you get a dye to attach to an antibody? You need to add another antibody.
This “secondary” antibody has a dye molecule attached to one end. Its other end can bind to any other antibody made inside one particular type of animal: either all rabbits, or chickens, or goats, or mice, you get the idea. The result, in a staining protocol, is a sandwich-like chain with two antibodies crammed between the antigen and the dye that announces the reaction to the world.
That’s all for one test. At a minimum, any company pursuing this idea would have to figure out a way to embed those steps into the plastic they make the condom from. If they could do that, they would also have to find a way to make the condom absorbable enough to test a little semen or vaginal fluid without becoming so porous that it let those fluids seep all the way through. Multiple layers might work, but in general, condom manufacturers are trying to find ways to make their product thinner and stronger, not partly porous.
To put multiple tests with multiple dyes into one condom is even more of a technical nightmare. In the lab, it’s possible to stain more than one protein at a time using different dyes, but it’s a delicate operation—you need to use antibodies raised in different species to avoid cross-reactions and false positives. In a condom, all the first line of antibodies would be human ones, and the secondary antibodies, each carrying a different dye, wouldn’t be able to tell them apart. One possible solution might be to put discrete test spots all around the condom, each one specific to a different kind of infection.
--- Looks like this is a way's off I guess.