raschemmel:
...the TC4427 was designed to drive mosfets. It works fine when used that way.Put 12V on Vdd and drive it with a 5V output from the arduino and you will see 12V on the output.
The TC4427 datasheet specifies the "Supply Voltage Operating Range" as 4.5V to 18V. So, it should work at 5V. And it should drive an LED the way the OP is attempting.