Synthesis and characterization of nano-gold doped and molecularly imprinted polymers modified electrochemical sensor for selective detection of melamine

An electrochemical sensor was prepared based on nano-gold doping and molecularly imprinted polymer modification, and its specific melamine performance was studied. Firstly, melamine molecularly imprinted polymer was prepared by noncovalent method with melamine as template molecule, methacrylic acid as functional monomer, ethylene glycol dimethacrylate as crosslinking agent and 2,2-azobisisobutyronitrile as initiator. Gold nanoparticles were introduced into polymer to form gold nanoparticle doped melamine imprinted complex (AuNPs@ MIPs), and then the polymer was mixed with graphite powder and liquid paraffin to make carbon paste, which was filled into polytetrafluoroethylene electrode cavity to prepare electrochemical sensor (AuNPs@ MIPs/ CPE). Under the optimum experimental conditions, the linear detection range of the sensor for melamine was 1 ×10-9-1 × 10-4 mol/ L, and the detection limit was 57. 4 nmol/ L. Three structural analogues and three interfering ions were used to determine the selectivity of the sensor, and the results showed that the sensor had good selectivity for melamine. Finally, the prepared sensor was applied to the detection of melamine in fresh dairy products, and the recovery rate was 87% -102%. © 2021, Youke Publishing Co.,Ltd. All rights reserved.