Multicomponent graphene oxide dispersions for thin reduced graphene oxide film formation

Insufficient wettability is one of the significant obstacles to the development of flexible and organic electronic devices based on carbon nanomaterials. It is especially important for graphene oxide, since commercially available graphene oxide is often provided in the form of aqueous suspensions. We showed the possibility of improvement of graphene oxide suspension wetting properties by adding such extra components as N-methylpyrrolidone, dimethylacetamide, and two types of thinners for lacquer paints to commercially available graphene oxide suspensions. In all cases, successful decrease of the contact angle was demonstrated. We also studied the effect of additional components on evaporation time that is important for formation of thin, uniform films using spin coating. Evaporation time of dispersion media components can vary from 3 to more than 40 times. The stability of suspensions with N-methylpyrrolidone and dimethylacetamide has also been demonstrated for more than 2 months and about 1.5 months when using a thinner for lacquer paints. Graphene oxide film from 0.93 mg/ml suspension with lacquer thinner was successfully deposited and reduced for BGTE transistor formation. Reduced GO film acted as an n-type semiconductor with 2 − 8 × 10^–3 cm²/V*s⁻¹ mobility. Reduced GO film was also used for aptamer immobilization to form biosensor, selectively sensitive to thrombin in 0.1–5 µM range with 35–80 s response time.