A terror plot to bomb the London Underground or Westfield shopping centre was foiled shortly before the 10th anniversary of the July 7 attacks, a court heard.
Counter terrorism officers were alerted to the plan after Mohammed Rehman, under the name Silent Bomber, asked Twitter followers for advice on which of the two targets to choose, jurors were told.
Rehman, 25, is on trial at the Old Bailey with his wife Sana Ahmed Khan, 24, charged with preparing terrorist acts on or before May 28 this year. He is also charged with possessing an article for terrorist purposes.
Opening the trial, prosecutor Tony Badenoch QC told jurors that when the couple were arrested on May 28, "substantial quantities of chemicals and bomb-making wherewithal" were recovered from Rehman's home.
Khan had helped buy these chemicals knowing they were to be used to make a bomb, jurors were told.
Mr Badenoch said the pair had a "common interest" in violent and extreme Islamic ideology and had repeatedly researched 7/7 bombers, the court heard.
They also developed a keen interest in Islamic State and Rehman's online research showed he approved of their atrocities and "wished to play his own part", jurors were told.
On May 12 he allegedly posted a public tweet using the handle Silent Bomber with a profile picture of Jihadi John saying: "Westfield shopping centre or London underground? Any advice would be appreciated greatly."
The post was seen by counter terrorism, who arrested the couple 16 days later.
The prosecutor said: "The evidence suggests that the London Underground may well have been on his mind as a potential target as he was particularly fixated with the events of 7/7 and he referred to Shehzad Tanweer, one of the 7/7 suicide bombers, as his 'beloved predecessor'."
On the day of the tweet, he had repeatedly trawled YouTube for material about the London bombings and Tanweer, the court heard.
Rehman also tweeted a link to the al Qaida uncensored media released about the 7/7 bombings at the same time as he sought advice on "Westfield or London Underground", the court heard.
Rehman, of Radstock Road, Reading, and Khan of Hutton Close, Reading, deny wrongdoing.