Does Any Supplication to Allah Require a Human Intermediary?
No, prayer does not require a human intermediary.
Evidence from the Noble Qur'an
{And when my slaves ask you (O Muhammad) concerning Me, then I am indeed near (to them by My knowledge)}, {Soorah al-Baqarah, verse 186]
Evidence from the authentic Sunnah
((You pray to the one who hears all and He is near and He is with you)), [Transmitted by Muslim]