Gold nanoparticle-dotted, ionic liquid-functionalised, carbon hybrid material for ultra-sensitive detection of bisphenol A

Environmental contextBisphenol A, an important industrial material widely used as a plasticiser, fire retardant and resin polymer material, can cause endocrine disorders and precocious puberty. We developed a portable and efficient method for determining bisphenol A, and apply it to the detection of bisphenol A in bottles for infants and young children. AbstractA highly effective electrochemical sensor was developed for the highly sensitive detection of bisphenol A (BPA). The sensor is based on a glassy carbon electrode modified with a composite comprising 1-butyl-3-methyl imidazole hydrobromide (an ionic liquid, IL)-functionalised grapheme oxide (GO) to which gold nanoparticles (AuNPs) and carboxylic acid-functionalised carbon nanotubes (CNT) were absorbed. The negatively charged carboxylic acid-functionalised CNTs and AuNPs are adsorbed on the positively charged GO-IL composite film by electrostatic adsorption. The as-prepared GO-IL-CNT-AuNP hybrid nanocomposites exhibit excellent water solubility owing to the high hydrophilicity of the GO-IL components. Moreover, the excellent conductivity is attributed to the good conductivity of the IL, CNT and AuNP components. The hydrid materials enhance the preconcentration efficiency of BPA and accelerate the electron transfer rate at the electrode–electrolyte interface, as such the resultant fabricated electrochemical sensor displays a fast, stable and sensitive detection performance for trace amounts of BPA. Differential pulse voltammetry was used as a sensitive analytical method for the determination of BPA, and a much wider linear dynamic range of BPA determination was found between 5 and 100nM. The limit of detection for BPA was found down to 1.5nM based on a signal to nose ratio of 3. The modified electrode was successfully employed to detect BPA extracted from a plastic water bottle and milk carton.