I use the below code to convert from unicode to utf-8:
Encoding unicode = Encoding.Unicode;
Encoding UTF8 = Encoding.UTF8;
byte[] unicodeBytes = unicode.GetBytes(stringResp);
byte[] UTF8Bytes = Encoding.Convert(unicode, UTF8, unicodeBytes);
string stringResp = UTF8.GetString(UTF8Bytes, 0, UTF8Bytes.Length);
But the special characters doesn't show, only their unicode code (\u00c1 for Á for example). If I look manually the next string ("\\u00c1") and replace it for Á it works. Does someone knows why and how I can make an automatic conversion?