El-Hassan, who has a Masters degree in pharmacy from University College London, used her expert knowledge of chemicals to help Mohammed research and stockpile the ingredients needed for a bomb, the Old Bailey heard.
Prosecutor Anne Whyte, QC, said: “Munir Mohammed appears to have met Rowaida El-Hassan, a qualified pharmacist, through a Muslim dating website.
“Their communications with each other demonstrated an emotional attachment and a shared extremist ideology.
“They exchanged materials and views at the time, we say, Mohammed was planning to perform an attack of his own, motivated and inspired by what he had seen and heard on social media.”
She added: “Rowaida El Hassan had a professional knowledge of chemicals because of her professional training and qualifications.
“She assisted Mohammed by providing him with information about chemical components required for bomb making and how to source them and she assisted his online research about the manufacture of ricin using castor beans.
“In doing so she supported him in his engagement with attack planning.”
They are jointly charged with an offence under section 5 of the Terrorism Act 2006 – preparation of terrorist acts.’
Counter terror officers found bomb manuals and instructions for ricin and mobile phone detonators when they raided Mohammed’s Derby home on 12 December last year, it is said.
They also discovered 200ml of hydrogen peroxide and 500ml of hydrochloric acid - two of the components needed to make an unstable explosive.
When another team raided El-Hassan’s home in Willesden, northwest London, on the same day they found a 1 litre bottle of drain cleaner which contained Sulphuric acid at 91 per cent purity - another explosive component.
Ms Whyte said: “Both of them possessed material useful to someone wishing to manufacture improvised explosive devices – devices that are designed to injure or kill in an indiscriminate way.
“Both of them had also been in possession of videos which gruesomely and variously depicted the murder, sometimes multiple murder of prisoners in the custody of an organisation, familiar to you as Islamic State.
“These videos were designed to provide ideological justification for such acts of violence.”
The court heard Mohammed had been radicalised after speaking to a Facebook contact called Abubakr Kurdi, a suspected IS commander who has celebrated terrorist atrocities in Nice, Normandy and Orlando and called for lone wolf attacks throughout the world.
Ms Whyte continued: “In his communications with Kurdi, Munir Mohammed pledged his obedience to Kurdi and therefore by implication to IS.
“He requested, using basic code, the receipt of bomb making instructions and had expressed willingness to participate in ‘a new job in the UK’ - in other words, in an act of terrorism involving extreme violence.”
Mohammed, of Leopold Street, Derby, and El-Hassan, of Willesden Lane, Willesden, each deny one count of preparing terrorist acts between November 2015 and September last year.