Here is quote from a scholarly source I found on JSTOR on Plotinus and Gnosticism with two footnotes:
In Plotinus' system too identification with the One is the ultimate goal of human endeavor. The self in its upward flight does not stop at the level of nous in a mere contemplation of the highest existence-as do the redeemed in Christianity. Plotinus too holds something like the Gnostic notion of the divine spark when he says, in more Aristotelian language, that ascent to and union with the One means the reawakening of the psyche's potentialities?  or when he declares that the supreme part of the psyche is forever united with the One.
21 Enn. VT ix 11, IV viii 1.
22 Enn. I1 ix 2
Citation: Katz, Joseph. “Plotinus and the Gnostics” (Journal of the History of Ideas, Vol. 15, No. 2. Apr., 1954) pp. 289-298.