M20 pilot reports taxiing into a tie down hole on a ramp at GSO; causing the nose wheel to become trapped and the propeller to contact the ground.

Narrative

While taxiing from hangar to the ramp via K1 Taxiway; there are three holes in ramp area created for subsurface tie downs. I saw and avoided two; but not the third one; which had a tie down coiled inside the hole. My nose gear fell into the hole. I subsequently shut down the engine and climbed outside where I examined my nose strut and propeller. The strut looks fine; but the prop showed slight scrapes on the tip. A lineman working for the FBO helped me extract the nose gear from the hole. At first I was not sure there was even a strike at all and subsequently performed a run up and test flew the plane. I did not notice any issues with engine or prop performance. Once back on the ground I took pictures of the holes and my prop and have grounded the plane until a licensed A&P gives me the ok. I am having the FBO MRO facility examine and determine if this is a 'prop strike' as defined by SB and AD and what the next step should be; whether this requires just a dressing of the prop or T&I.