Yes, free nucleoside triphosphates absorb at around 260nm too. Here's the info
from the back of the Promega protocols guide:
Absorbance maximum nm (pH7) Absorbance for 1M solution
dATP 259 15 200
dCTP 271 9 300
dGTP 253 13 700
dTTP 267 9 600
Neil Saunders