Remove backslash from json string wp8

Question

I have converted an object into string in wp8,by using

string str=JSONConvert.SerializeObject(object);

Now I am getting a string like this:-

{\"catGroup\":[{\"category\":{\"cgsId\":9,\"cgsName\":\"Ignition & Engine Filters\",\"values\":null}..

I want to remove the backslash from the string.I have used str = str.Replace(@"\","");

But still I am getting the string containing backslashes. How to remove this?