It seems to me that, rather than making straws and drinks that do this, it would be better to see if it could be incorporated into some kind of nail polish that, once dried, could detect this.<p>I suggest nail polish for two reasons. One is that it removes the need to carry specialized tools: once you've done your nails, you can test 10 drinks and leave the bottle at home. Not having to carry a tool is somewhat more convenient, but it also means the tool can't be forgotten, lost, stolen, or tampered with.<p>The other advantage is discretion. It's not difficult, with a setup like this, to test a drink without others knowing what you are doing. It could be argued that people shouldn't mind being tested, but from a pragmatic standpoint, the kind of person who spikes a drink is the kind of person who could very easily become dangerous if they know they're being put to the test. A discreet test, therefore, is a safer test, and since these tests are supposed to be all about safety, it follows that a discreet test is also a better test.