Vucinic has played a key role in their form reversal under coach Claudio Ranieri.
He said: "There is a sparkling atmosphere in the dressing room. It's wonderful to be top of the table.
"We have the means and the desire to stay there. Few teams in the world would have been capable of completing a comeback like ours.
"It's credit to an extraordinary group of players. I continually think about the Scudetto. It's a fixed point in my mind.
"Totti will be our secret weapon, starting from the derby. I hope to score."