Rational design and application of molecularly imprinted sol–gel polymer for the electrochemically selective and sensitive determination of Sudan I

An electrochemical strategy on the basis of rationally designed molecularly imprinted sol–gel polymer embedded with gold nanoparticles (AuNPs) is developed for the specific and sensitive determination of Sudan I. The rationally designed sensing Sudan I imprinted sol–gel was prepared by mixing Sudan I with 3-aminopropyltriethoxysilane, tetraethoxysilane, chitosan, and AuNPs, followed by copolymerization and extraction of the template molecules. The hybrid forming membrane was characterized by SEM and FTIR-ATR, and used for the linear sweep voltammetric (LSV) determination of Sudan I in water/ethanol solutions. The LSV responses exhibited high sensitivity and selectivity, as discriminated from Sudan I analogues. Under optimal experimental conditions, LSV peak currents were linearly proportional to the concentrations of Sudan I in the range from 0.1 × 10−7 to 1.0 × 10−5 M, with a detection limit of 2.0 × 10−9 M. The strategy is generally applicable in developing sensitive, selective, and moreover, reusable electrochemical sensors for quantitative determination of electroactive species.