'one remark' is correct and usable in written English.
You can use it to refer to a single statement, comment, or opinion. For example: My teacher made one remark about my essay that has stuck with me ever since.
One remark in particular stuck with me.
One remark dissolved into the next.
One remark was expunged or amended by a different author, whose own statement was in turn refuted just as passionately.
One remark by Russia's culture minister, Vladimir Medinsky, who, earlier this year, said openly that he did not like Leviathan, seems especially to irritate.
One remark has continued to elude proof and remains one of the greatest conjectures in mathematics: the claim that the nonreal zeros of the zeta function are complex numbers whose real part is always equal to 1/2.
One remark however ought not to be omitted.
No? OK, yeah, one remark, sorry.
He added, "One remark of Faÿ's I will never forget.
All this for me is an excuse to look at this one remark here.
With one remark, all his prejudices about Americans had been confirmed.
