The Brazilian defender moved to Stamford Bridge in January 2011 and has recently been linked with a move to Barca.
Luiz told a Spanish newspaper: "I would be lying if I said I know nothing.
"I am aware, not least because for months there have been constant rumours about Barca's interest.
"What I can confirm is that I have not negotiated anything and no one has submitted a concrete offer. I am 100 per cent a Chelsea player.
"Barca are a great team that play fantastic football. Every player would love to play for Barcelona, but I am with Chelsea and I have an obligation to my club."