Border collie mix with blue collar and white heart patch

Yesterday around 3pm I lost my border collie mix near the State Capitol on Court Street in Salem. He's about 40 pounds, brown and white, with a white heart-shaped patch on his chest and a small scar above his right ear. He wears a bright blue collar with a bone-shaped tag that says MAX, and he has one blue eye and one brown eye. He gets anxious when dogs bark and bolted when a street vendor's noise spooked him, and I couldn't catch him. If you find him, please contact me — he means the world to me.