A rapid and sensitive tailor-made electrode based on a gold nanoparticle (AuNP)-modulated hydrophilic sodium dodecylsulfate (SDS)-wrapped graphene (G)-tolonium chloride (TC) (GSTG) nanocomposite was designed step-by-step in an easy and green way for the detection of ascorbic acid (AcA). At a GSTG/chitosan(CHIT)-modified glassy carbon electrode (GCE), the oxidation potential of ascorbic acid not only appeared at a lower overpotential +200 mV vs. Ag/AgCl, but also the anodic current was enhanced about 20.8 times as compared to a bare GCE. Under optimal conditions, a GSTG/CHIT-modified GCE-based electrochemical sensor was fabricated for electrocatalytic oxidation of ascorbic acid with a high sensitivity of 4017.0 μA mM−1 in a wide linear range of 3 × 10−4–1 × 10−2 mM. The limit of detection was calculated to be 0.07 μM and the sensor was also investigated for the determination of ascorbic acid in real samples (Vitamin C tablets) with satisfactory results.
