After a goalless draw in the play-off first-leg in Istanbul, where midfielder Aaron Ramsey was sent off late on for a second yellow card, Wilshere insists the tie is in the balance.
"It was a hostile atmosphere, but I think we battled well and showed a different side to our game, especially at the end when we went down to 10 men, it was tough, so we did well," Wilshere said.
"They worked just as hard as we did last year to get themselves into this position, so they are not going to just turn up (at the Emirates Stadium) and throw all of that hard work away. It is not going to be an easy game and we can't take it for granted.
"They are going to come full of confidence from their performance in the first game and we are going to have to start how they did and take the game to them."
Arsenal are bidding to book their ticket to the Champions League group stages for the 17th consecutive season.
Wilshere added: "We always want to be in the Champions League and to attract players who can be in the Champions League. We know how big a game it is, and we will treat it as a cup final."
Arsenal will be boosted by the return of German World Cup winning trio Per Mertesacker, Lukas Podolski and Mesut Ozil for the return leg.
Wilshere said: "Having won the World Cup can have an impact, but the Germans have got a fantastic mentality anyway.
"Last year, you saw that - they are great characters to have in the dressing room. We are looking forward to getting them back and it is going to make our squad even stronger."