How to make my dog only respond to me?

my family got a golden retriever mix between american and english and he is very very smart. we tought him at least 7 tricks in less than two weeks. some within a couple of minutes. i also tought him a trick (idk if u could say its a trick but) where if i clap twice he comes to me and sits in front of me. now most of my friends and family all know the trick and are always trying to do it and it works. i wanted to know if ther is any way to teach him how to only respond to me, not to anyone else, not to be selfish, but as an obediance kind of thing