A.T. Robertson Commentary John 3:1

"Now there was a man of the Pharisees, named Nicodemus, a ruler of the Jews:" — John 3:1 (ASV)

Now (δε). So often in John δε is explanatory and transitional, not adversative. Nicodemus is an instance of Christ's knowledge of men (2:25) and of one to whom he did trust himself unlike those in 2:24. As a Pharisee "he belonged to that party which with all its bigotry contained a salt of true patriotism and could rear such cultured and high-toned men as Gamaliel and Paul" (Marcus Dods).

Named Nicodemus (Νικοδημος ονομα). Same construction as in 1:6, "Nicodemus name to him." So Re 6:8. It is a Greek name and occurs in Josephus (Ant. XIV. iii. 2) as the name of an ambassador from Aristobulus to Pompey. Only in John in N.T. (here, 7:50; 19:39). He was a Pharisee, a member of the Sanhedrin, and wealthy. There is no evidence that he was the young ruler of Lu 18:18 because of αρχων (ruler) here.