Abstract: A novel molecularly imprinted electrochemical sensor for rapid?detection of quinoxaline drugs was prepared using nanosized silver sol and graphene as electrode modification materials, olaquindox as template molecule, and o-aminophenol and resorcinol as composite functional monomers. Using ultraviolet (UV) absorption spectroscopy, we selected the optimal functional monomer, and studied the interaction between template molecule and functional monomer. The preparation conditions were optimized by electrochemical analysis and the analytical performance of the sensor was evaluated. The template molecules were efficiently eluted in 20 min with ethanol-0.4 mol/L NaOH aqueous solution (3:1, V/V). The contents of four quinoxaline growth promoters were indirectly determined by measuring changes in response current with K3[Fe(CN)6] as electroactive probe. The results showed that the sensor displayed high sensitivity and selectivity to olaquindox, and could also specifically adsorb its structural analogues; the recoveries of spiked samples were between 89.05% and 100.86% with relative standard deviations (RSDs) of 1.03%–3.11% (n = 5), and the sensor was successfully applied to sensitive and rapid detection of quinoxaline growth promoter residues in animal origin foods.

Key words: olaquindox; quinoxaline growth promoters; nano-modified materials; molecularly imprinted technology; electrochemical sensor; rapid detection