Possible invention idea?

I'm not nearly knowledgeable enough about biochemistry to know if this would even be possible given the current state of the technology, but last night before bed, I found myself thinking:

"It would be really nice if a person with food allergies could get test strips that they could dip into a food they were concerned about, and it would turn color if the allergen was present."

I was thinking about the glucose test strips we use in one of the labs I do - they are a product sold for diabetics, so they can test their urine. There are also color-changing tests for lead in paint, and I am sure other things I am not thinking of.

But what nice peace of mind that would be - "I don't know for sure if this broth might have miso in it, so let me check." or "Could there be peanut proteins in this smoothie?" (I can see how it would only work for liquid things).

Or, even better - something like one of those Star Trek quick-diagnosis devices, where you could stick a  probe into the questionable food, it would sample and quick-analyze it, and tell you. They could even, perhaps (I'm dreaming here, of course) be programmed so multiple users with different allergies could use them - so if you are allergic to eggs and your partner has a gluten sensitivity, you could both use the same sensor with different settings or modes.

Theoretically it should be possible: have some kind of thing that would bind to the specific protein and either change color or (if it were an electronic sensor) send some kind of impulse if it were present.

Technological-minded food chemists or food engineers? If you could get on that project and make it happen I'd be very appreciative.

Because given Monday's issues, I think I'm going to have to be WAY more careful about "natural flavors" in things.

Also, an aside: my new favorite "grab a meal quick while I'm out shopping place" (Panera Bread) has SUPER detailed ingredient information on their website - they list every flavoring in things. (And they have good nutritional info so I can look up sodium). Yay Panera Bread, and you're going to be getting more of my business in the future because of that. (Though sadly? Their new "broth bowls," which look good, are all made with miso, which gives me terrible headaches - so, none of their broth bowls for me.)

The nearest one right now is in Sherman but I keep hoping we'll eventually get one right here. I'm thinking it would do well, given the presence of the university....