Biosensors based on immobilised enzyme propose determination of analytes with excellent selectivity and sensitivity while their stability is still a challenge. Thus, promoting the selective, sensitive, rapid, inexpensive, and reliable strategies to fabricate new biosensors is a critical issue for the analyte determination. In this study, a novel functionalised graphene, methacrylated graphene oxide (MeGO), was utilised as an advanced biosensing device for non-enzyme determination of ascorbic acid (AA). The MeGO-based sensor was fabricated by a very simple coating approach on a glassy carbon electrode. The cyclic voltammogram of the new biosensor demonstrated a pair of well defined, reversible, and stable peaks for redox systems in a buffer solution. The exploited nanobiosensor depicted high catalytic bioactivity towards the oxidation of AA at a positive potential in the buffer solution. The biosensing characteristics of the developed nanobiosensor presented excellent sensitivity, low limit of detection, and wide linear range. To the best of this study's knowledge, this is the first research that uses MeGO in biosensing applications. Moreover, the sensing characteristics of the device are compared with other developments previously reported for non-enzyme AA sensors.