The pristine graphene produced by liquid exfoliation of graphite in mixed solvent and its application to determination of dopamine

The pristine graphene can be easily prepared in isopropanol-water mixture with salts as assistant via liquid-phase exfoliation method. The concentration of graphene dispersion reaches as high as 0.565 mg/mL. The graphene film prepared by drop-casting method shows an excellent electrical conductivity (7.095 × 10 4  S/m). Furthermore, an electrochemical biosensor based on the pristine graphene shows high selectivity and sensitivity for the determination of dopamine. The linear detection range for dopamine is 2.5–1500 μM with detection limit of 1.5 μM. This method provides a potential process for preparing high-quality graphene ready-to-use in low-boiling point solvent.