Biosensor
A Biosensor is a device that detects chemicals or germs in the body using a biological sensor.
Think of it this way
A smoke alarm hangs on your kitchen wall. It has a small sensor inside that reacts to smoke. When smoke reaches the sensor, the alarm sounds. A biosensor works the same way, using a biological sensor to detect specific chemicals or germs.
Explaining biosensor by grade level
A biosensor is a tiny tool that can find things in your body. It can tell if you are sick. A doctor might use one to check your blood. It looks for germs or other small things that do not belong.