It is not permissible for a person who is in a state of impurity to touch a single aayah because the ruling on that is the same as the ruling on the Mus-haf. But if there are other things written alongside the aayah, as in books of Tafseer and Fiqh, then the ruling depends on which is the greater; if there is more Qur’aan than anything else, then it is haraam to touch it without wudoo’, but if there is more of writings other than Qur’aan, then it is permissible to touch it. 

Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him) said: “Anything on which there is Qur’aan comes under the same rulings as the Mus-haf if there is only Qur’aan on it, but if other things are written on it as well as Qur’aan, then the ruling depends on which is the greater. It is permissible to touch books of tafseer, hadeeth, fiqh and essays in which there is some Qur’aan.” (Sharh al-‘Uddah, 1/385).