However, he was nearing the end of his contract and hard-up Jags opted to offload one of their top earners.
"Dunfermline are an exciting side and create a lot of chances. Hopefully, I can get on the end of a few," Buchanan told BBC Radio Scotland.
The striker has agreed an 18-month deal, which is subject to a medical at East End Park on Friday.
Thistle hope to replace Buchanan with a player on loan from a Scottish Premier League club but manager Ian McCall is sad to see his first signing for the club move on.
"The first thing to stress is that, in an ideal world, we didn't want to lose Liam Buchanan," he told the club website.
"However, in the current financial climate I am in full agreement with the board in that it makes financial sense, especially as he had only a few months of his contract to run. Liam was on a similar deal that we had Gary Harkins and Marc Twaddle on and the reality is that we simply can't afford that at the moment.
"Liam is a terrific lad with a great attitude and a real winning mentality. I've absolutely no doubt that he will go on and score plenty of goals for Dunfermline and I think it is the right move for him."
"It's ironic in a way that we are losing Liam at a time when it looks as if he is about to regain his best form. Had he not suffered two or three injuries during his time here at Firhill I'm quite sure he would have scored about double the number of goals that he did for us."
Source: BBC Sport
Source: BBC Sport