Are there any Biblical allusions to St. Raphael or Uriel outside of Tobit?
That will depend on who’s Biblical Canon one prefers to follow.
For most denominations, the answer would seem no.
However, Christians of the Ethiopian Orthodox Tewahedo Church and the Eritrean Orthodox Tewahedo Church accept the Book of Enoch as part of their canon. And the Book of Enoch definitely makes several illusions of Angel St. Raphael and the Angel Uriel.
By the 4th century, the Book of Enoch was mostly excluded from Christian biblical canons, and it is now regarded as scripture only by the Ethiopian Orthodox Tewahedo Church and the Eritrean Orthodox Tewahedo Church.
It is not part of the biblical canon used by Jews, apart from Beta Israel (Ethiopian Jews). While the Ethiopian Orthodox Tewahedo Church and Eritrean Orthodox Tewahedo Church consider the Book of Enoch as canonical, other Christian groups regard it as non-canonical or non-inspired, but may accept it as having some historical or theological interest.
It is today wholly extant only in the Ethiopian Ge'ez language, with earlier Aramaic fragments from the Dead Sea Scrolls and a few Greek and Latin fragments. For this and other reasons, the traditional Ethiopian belief is that the original language of the work was Ge'ez, whereas modern scholars argue that it was first written in either Aramaic or Hebrew, the languages first used for Jewish texts; Ephraim Isaac suggests that the Book of Enoch, like the Book of Daniel, was composed partially in Aramaic and partially in Hebrew: No Hebrew version is known to have survived. The book itself asserts that its author was Enoch, before the biblical flood.
The most complete Book of Enoch comes from Ethiopic manuscripts, maṣḥafa hēnok (መጽሐፈ ሄኖክ), written in Ge'ez, which were brought to Europe by James Bruce in the late 18th century and were translated into English in the 19th century.- Book of Enoch
It has also been alleged that the First Epistle of Peter (1Peter 3:19–20) and the Second Epistle of Peter (2Peter 2:4–5) make reference to some Enochian material.
In the Epistle to the Hebrews (Hebrews 11:5) Enoch and that he received testimony is mentioned which may allude to his book.
19 After being made alive, he went and made proclamation to the imprisoned spirits— 20 to those who were disobedient long ago when God waited patiently in the days of Noah while the ark was being built. In it only a few people, eight in all, were saved through water. - 1 Peter 3:19-20
4 For if God did not spare angels when they sinned, but sent them to hell, putting them in chains of darkness[b] to be held for judgment; 5 if he did not spare the ancient world when he brought the flood on its ungodly people, but protected Noah, a preacher of righteousness, and seven others.- 2 Peter 2:4-5
5 By faith Enoch was taken from this life, so that he did not experience death: “He could not be found, because God had taken him away.”[a] For before he was taken, he was commended as one who pleased God. - Hebrews 11:5
Some ancient writers, including Gelasius (verse 2,21,17) and Origen (De principiis, III,2,1), cite the Assumption of Moses with reference to the dispute over the body of Moses, referred to in the Epistle of Jude 1:9, between the archangel Michael and the devil.
9 But even the archangel Michael, when he was disputing with the devil about the body of Moses, did not himself dare to condemn him for slander but said, “The Lord rebuke you!” - Jude 1:9
St. Jude quotes directly from the Book of Enoch, part of the scripture of the Ethiopian and Eritrean churches but rejected by other churches. He also cites Enoch's prophecy that the Lord would come with many thousands of his saints to render judgment on the whole world.
Taking into consideration all the above, I will leave it to the readers to decide if there are any biblical allusions to St. Raphael or the angel Uriel outside of Tobit!
Raphael features prominently in the deuterocanonical Book of Tobit. The Book of Tobit is accepted as canonical by the Roman Catholic Church, the Anglican Communion, the Eastern Orthodox Church, and the Oriental Orthodox Church.
The Book of Enoch, which presents itself as written by Enoch, mentions Uriel in many of its component books. In chapter IX, which is part of "The Book of the Watchers" (2nd century BCE), only four angels are mentioned by name. Those angels are Michael, Uriel, Raphael, and Gabriel (though some versions have a fifth angel: Suryal or Suriel). However, the later chapter XX lists the names and functions of seven angels. Those angels are "Uriel, one of the holy angels, who is over the world and over Tartarus", Raphael, Raguel, Michael, Saraqâêl, Gabriel, and Remiel.
The Book of the Watchers as a whole tells us that Uriel, Raphael, and Gabriel were present before God to testify on behalf of humankind. They wish to ask for divine intervention during the reign of the fallen grigori (fallen watchers). These fallen take human wives and produced half-angel, half-human offspring called the nephilim. Uriel is responsible for warning Noah about the upcoming great flood.
Then said the Most High, the Holy and Great One spoke, and sent Uriel to the son of Lamech, and said to him: " and tell him in my name 'Hide thyself!' and reveal to him the end that is approaching: that the whole earth will be destroyed, and a deluge is about to come upon the whole earth, and will destroy all that is on it."
After judgment has been brought upon the nephilim and the fallen ones (see The Book of Giants), including the two main leaders Samyaza and Azazel, Uriel discusses their fates:
And Uriel said to me: "Here shall stand the angels who have connected themselves with women, and their spirits assuming many different forms are defiling mankind and shall lead them astray into sacrificing to demons 'as gods', (here shall they stand,) till 'the day of' the great judgment in which they shall be judged till they are made an end of. And the women also of the angels who went astray shall become sirens.' And I, Enoch alone, saw the vision, the ends of all things; and no man shall see as I have seen."
Uriel then acts as a guide for Enoch for the rest of the Book of Watchers. He fulfills this capacity in many of the other books that make up Enoch. - Uriel
Many of the Early Church Fathers accepted Enoch as divinely inspired. Simply read Wikipedia’s article on this subject matter: Reception of the Book of Enoch before modern times!