Novel electrochemical sensor for determination of propyl gallate based on poly(γ-aminobutyric acid) incorporating gold nanoclusters

Propyl gallate (PG), a common anti-oxidant used in food, has garnered extensive attention due to its possible harm to human health. Herein, a highly sensitive sensor for determination of PG in foodstuffs was fabricated by electropolymerizing γ-aminobutyric acid (GABA) and electrodepositing gold (Au) on a glassy carbon electrode (GCE). Scanning electron microscopic (SEM) images showed that the poly GABA formed a layer of uniform membrane, and the deposited Au was needle-like nanoclusters (AuNC). The electrochemical experiments showed that, under the optimal conditions, the modified electrode can be used for determination of PG in a wide concentration range from 0.06 to 3.6 μmol/L, with a correlation coefficient (R) of 0.9990 and a detection limit of 0.001 μmol/L (S/N = 3). The applicability of the sensor was verified by detecting PG in food samples, such as instant noodles, biscuits and edible oils, with excellent specificity and good recoveries (94.0–100.6 %), indicating that the sensor has application prospects in food safety control.