There is 1 or 2 of them, but from what I recall they are fairly expensive, must be paired with a smartphone via an app, and are no good for indicating how wet you are (only if you are or not). Which means they aren't any good for telling you when you should change either.
They're really intended for institutions with the mentally disabled or physically incapacitated. I personally wouldn't bother with them if I were you. I find a quick and discrete pinch to the seat of your diaper is a good way to tell how wet you are and how long before you'll need to change. It's just a matter of making it a habit, which would be hindered if you're also using a sensor.
If your real worry is leaks then you'll be better off using a decent diaper (never ever use anything store bought unless you have minor or occasion stress leaks). I personally recommend Betterdry (or Crinklz of you want fun prints), which is cheaper than Depends on a per-day basis, and way more reliable/comfortable. Everyone is different though, so expect you'll need to test out a few different brands before you'll find the right one. And with any diaper, pair it with a Gary Activewear PUL pant. They are real savers for discretness and containing leaks while helping you to notice them right away.
Lastly, make sure to read up on the other threads here. They are packed with excellent tips, tricks, and lessons learned.