Determination of allura red using composites of water-dispersible reduced graphene oxide-loaded Au nanoparticles based on ionic liquid

ABSTRACT

A facile route for producing reduced graphene oxide (RGO)-loaded Au nanoparticles based on ionic liquids (IL) has been proposed, in which the as-prepared RGO can be dispersed stably in water. With the assistance of IL, Au nanoparticles were uniformly and densely absorbed on the surfaces of the IL functionalised reduced graphene oxide (IRGO), forming a new composite of IRGO/Au with high dispersibility. This IRGO/Au composite enhanced its electrochemical signal obviously in the measurement of allura red in foods and exhibited a wider linear response ranging from 0.297 (0.0006 μmol L⁻¹) to 99.3 μg L⁻¹ (0.2 μmol L⁻¹) with lower detection limit of 0.213 μg L⁻¹ (0.00043 μmol L⁻¹) at a signal-to-noise ratio of 3. To further study the practical applicability of the proposed sensor, the modified electrode was successfully applied to detect allura red in five kinds of common foods and the assay results were in a good agreement with the reference values detected by HPLC.

KEYWORDS:

• Allura red
• determination
• water-dispersible
• ionic liquid
• reduced graphene oxide
• gold

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

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Additional information

Funding

This research was supported by National Natural Science Foundation of China: [Grant numbers 51501124 and 51602212] and Basic Research Project in Shanxi Province: [Grant number 2015021071].