Quickfire goals from Marko Pjaca and Dani Alves helped the Serie A champion to a 2-0 win at the Estadio Dragao three weeks ago, with Porto likely needing to score at least three goals to stand a chance of reaching the last eight.
Barca's turnaround against PSG last week - from 4-0 down to win 6-5 on aggregate - may give Porto's travelling fans hope, but Nuno says the comparison will not help him plan a victory against Massimiliano Allegri's side.
"We are behind in the tie but there are no parallels to be drawn with what Barcelona achieved last week," he told a news conference. "We must consider this as a completely different, one-off game.
"Beginning in the play-offs in August, we've come a long way to get to this point and the team can be proud of what they have achieved so far.
"We have a clear idea of how we want to approach the game; we want to attack, be effective at both ends of the field and give our creative players license to influence the proceedings as best they can.
"We have come here in good form, high spirits and we have the belief to get the result we want. Everyone knows how strong Juventus are on home soil. Their records speak for themselves but eventually someone will beat them here and it could be us that does it."
Juventus v Porto - Key stats
2 - Gonzalo Higuain has scored only two goals in 21 UEFA Champions League knockout games. In the group stages, he has netted 13 goals in 38 games.
0 - In 13 previous instances, no team has progressed having lost the first leg of a UEFA Champions League knockout tie by a 2-0 scoreline at home.
18 - In its last five Champions League knockout ties away from home, Porto has conceded 18 times and scored just three in reply.
6 - Andre Silva has been directly involved in two-thirds of Porto's goals in this season's Champions League (six out of nine), scoring four and assisting two.
2 - No team has conceded fewer goals than Juventus this season in the Champions League, the Italian champion has let in just two across seven matches.