Direct Electrodeposition of Gold Nanostructures onto Glassy Carbon Electrodes for Non-enzymatic Detection of Glucose

• Dendrite-like gold nanostructures (DGNs) were obtained by a simple potentiostatic method.
• The morphology and structure of DGNs could be easily tuned through the deposition conditions.
• The DGNs with high ESA show superior electrocatalytic activity to glucose oxidation.
• DGNs exhibit excellent stability and selectivity for nonenzymatic glucose detection.

Dendrite-like gold nanostructures (DGNs) were directly electrodeposited onto the surface of a glassy carbon electrode (GCE) via the potentiostatic method without any templates, surfactants, or stabilizers. The effects of the deposition time, potential and the concentration of precursor solution on the evolution of the nanostructure and on the electrocatalytic activity of the DGNs were systematically investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical methods including cyclic voltammetry, linear voltammetry and chronoamperometry. The results confirmed that DGNs have good electrocatalytic activity towards the electro-oxidation of glucose in a neutral phosphate buffer solution (PBS, pH 7.4). A non-enzymatic glucose sensor fabricated with the DGNs as an electrocatalyst showed a quick response (less than 2 s), a low detection limit (0.05 mM), a wide and valuable linear range (0.1 - 25 mM), a high sensitivity (190.7 μA cm−2 mM−1) and good repeatability and stability. In addition, the commonly interfering species, such as ascorbic acid (AA), uric acid (UA), and 4-acetaminophen (AP), did not cause obvious interference because of the use of a low detection potential (0.15 V vs. Ag/AgCl). This work demonstrates a simple and an effective sensing platform for the non-enzymatic detection of glucose.