Context: the character is in a store, searching for something fun to do.
Full sentence: 俺は何か面白いものはないか、店内を見回してみた。
My question is about the first part of the sentence, "俺は何か面白いものはないか", specifically about "ものはないか".
The character seems to be talking something on the lines of:
"Is there something of interest for me?"
From my understanding, もの here is used here to mean thing/object, so "something that is 面白い", but I'm not sure about the はないか part of the sentence, is the は a particle? If so, why is there two in the same sentence, since we have "俺は" already. If not, is 「はないか」 a expression with it's own meaning?