No, they are not the same thing. A carbon monoxide detector is a device that detects the presence of carbon monoxide gas (CO) to prevent CO poisoning. CO is a colorless and odorless compound produced by incomplete combustion, and elevated levels of CO can be dangerous to humans.
Radon is a colorless and odorless radioactive gas formed during the natural breakdown of uranium in soil, rock, and water. Radon can seep into your house through cracks and holes in the foundation. You can order a radon test kit and set it up yourself or you can hire a professional to do the test.