What is the value of 1985 copper nickel there is no silver plating?

Nickels are not struck in pure copper and they are not silver-plated. They're made of a solid alloy composed of nickel and copper.

What you have is a coin that has been altered or damaged in some way, either by someone plating it using a high-school chemistry set, exposing it to a chemical, or heating it to cause discoloration. In any case it won't have any numismatic worth except for its face value.

Another answer:

The 1985 Jefferson Nickel coin error is a pretty unique one. If you look at the picture to the right, you will notice that this 1985 nickel looks like it is copper. In fact, it partially is copper.

1985 Jefferson Nickel Coin Error

What caused this coin error?

Before the U.S. mint stamps a coin, it takes the planchet and heat them in an oven. The mint uses the same oven for all of its planchet. In this case, the U.S. mint placed the nickel planchet into the oven right after firing copper planchets. The copper molecules from heating the copper planchet must have remained in the oven. And, then these 1985 Jefferson nickels got copper on them during their firing.

That is how this 1985 Jefferson nickel coin error was made.

Sorry, pic from article did not come up.