"I want to make money," the affidavit quotes him as saying in one conversation.
Blagojevich also allegedly discussed placing his wife on corporate boards, where he speculated she might get paid as much as $150,000 a year.
"Like the rest of the people of Illinois, I am saddened and sobered by the news that came out of the US attorney's office today."
He also allegedly said he might get money up-front, as much as $500,000, from a candidate to replace Obama.
"If I don't get what I want and I'm not satisfied with it, then I'll just take the senate seat myself," Blagojevich said, according to court papers.
Patrick J Fitzgerald, a prosecuting attorney, said in a statement that "the breadth of corruption laid out in these charges is staggering."
However Fitzgerald said that Obama was in no way implicated in the case.
"I should make clear the complaint makes no allegations about the president-elect whatsoever," he said.
Obama said on Tuesday he was not aware of any alleged corruption by Blagojevich.
"I had no contact with the governor or his office, and so I was not aware of what was happening," Obama said.
"Like the rest of the people of Illinois, I am saddened and sobered by the news that came out of the US attorney's office today," the president-elect said.
Al Jazeera's Rob Reynolds says the arrest follows a long tradition of corruption in Illinois politics.
"Blagojevich is the fourth Illinois governor to be arrested in the past 40 years, and his predecessor is currently serving a six year sentence in federal prison," Reynolds says.
Among those being considered for the senate post included Danny Davis and Jesse Jackson Jr, both US congressmen, the Associated Press news agency reported.
John Harris, Blagojevich's chief of staff, was also arrested and both men have also been charged with conspiracy to commit mail and wire fraud and solicitation of bribery.
Alleged corruption in Blagojevich's administration has been the focus of a US government investigation involving an alleged seven million dollar scheme aimed at obtaining money out of companies seeking business from the state of Illinois.
Federal prosecutors have acknowledged they're also investigating "serious allegations of endemic hiring fraud" under Blagojevich.
Political fundraiser Antoin "Tony" Rezko, who raised money for the campaigns of both Blagojevich and Obama, is awaiting sentencing after being convicted of fraud and other charges.