A poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)-based electrochemical sensor for tert.-butylhydroquinone

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a readily available copolymer that comes as an aqueous dispersion with good processability. A flexible voltammetric sensor for the widely used food stabilizer tert.-butylhydroquinone (TBHQ) was constructed by using a film of PEDOT:PSS. The electron transfer efficiency of the electrode was enhanced by doping with dimethyl sulfoxide (DMSO), and mass transport at the electrode-electrolyte interface was increased by adding the cationic surfactant cetyltrimethylammonium bromide (CTAB) which acts as a sorbent for TBHQ. SEM, AFM, XPS, UV - vis and electrochemical analysis were conducted to characterize the properties of the electrode. After optimization of the experimental conditions, the electrode operated at a working potential of 0.17 V (vs. SCE) has a linear response in the 0.5-200 mu M TBHQ concentration range and a lower detection limit of 0.15 mu M (at S/N = 3). It was applied for the determination of TBHQ in spiked real samples, and recoveries ranged between 96.85 and 103.41%.