The 23-year-old Dutchman arrived from Feyenorrd in August 2015, but he has struggled for game time at Brighton, making only 13 appearances.
Brighton manager Chris Hughton told brightonandhovealbion.com: " The competition for places in our forward areas means that it has been very difficult for Elvis to play the number of matches he would have liked.
He has worked hard during his time here, but with his game time likely to be limited again, this is the best move for him."
Dutch-born Ghanian Manu has spent time on loan at Huddersfield Town and Go Ahead Eagles in the last two seasons. Manu will sign a two-year deal for the Turkish side.