Green and controllable strategy to fabricate well-dispersed graphene–gold nanocomposite film as sensing materials for the detection of hydroquinone and resorcinol with electrodeposition

The paper described a green and controllable strategy to fabricate well-dispersed graphene–gold nanocomposite film. To prepare graphene–gold nanocomposite film, graphene and gold nanoparticles were alternately electrodeposited on the surface of glassy carbon electrode. Since electrochemical technique offers control over reaction parameters and excellent repeatability, the amounts of graphene and gold nanoparticles for the each layer can be pre-determined by controlling concentrations of graphene oxide and chlorauric acid. The as-prepared graphene–gold nanocomposite film was characterized by infrared spectrum, scanning electron microscope, Raman spectrum and X-ray diffraction, and its electrocatalytic activity was estimated by Laviron's model. The apparent heterogeneous electron transfer rate constant of 37.67 ± 0.19 cm s−1 was obtained, indicating fast electron transfer of Fe(CN)64− to the electrode. Further, the film was investiaged as sensing materials for synchronously detection of hydroquinone and resorcinol. When the cencentrations are in the ranges of 1.6 × 10−8 to 1.2 × 10−4 mol l−1 for hydroquinone and 1.0 × 10−8 to 2 × 10−6 mol l−1 for resorcinol, differential pulse voltammetric peak current of the sensor linearly increases. The sensitivities of differential pulse voltammetric response are 30.5 μA μM−1 cm−2 for hydroquinone and 117.83 μA μM−1 cm−2 for resorcinol. The detection limits were found to be 5.2 × 10−9 mol l−1 for hydroquinone and 2.2 × 10−9 mol l−1 for resorcinol (S/N = 3). Proposed method is simple, sensitive and selective, it has been applied to the determination of hydroquinone and resorcinol in real water samples with a spiked recovery in the range of 96.0–103.4%.

► We reported firstly green and controllable strategy to fabricate graphene–gold composite. ► The strategy provides control over reaction parameters and excellent repeatability. ► The composite offers faster electron transfer than pure graphene and gold nanoparticles. ► The composite was used to fabricate sensor for detection of hydroquinone and resorcinol. ► The sensor displays the best sensitivity for hydroquinone and resorcinol up to now.