Original Articles: 2014 Vol: 6 Issue: 11
Selective melamine sensor based on nanoporous carbon paste/molecularly imprinted polymer
Abstract
Selective melamine sensors based on nanoporous carbon paste /molecularly imprinted polymer have been studied. The study begins with the synthesis of MIP monomer mixture of methacrylic acid (MAA), and ethylene glycol dimethacrylate (EGDMA) cross linker, benzoyl peroxide initiator, and melamine template. Membrane electrodes are fabricated by mixing nanoporous carbon and MIP with a certain ratio of inserted into the electrode surface. The optimization of sample measurements which includes melamine test of pH value of a solution pH and membrane composition. Further characterization of the electrodes was done by determining the Nernst factor, measurement range, selectivity, and lifetime. Validation method was done by determining the accuracy, precision, and the detection limit. Based on the data from FTIR, has been successfully synthesized MIP with BET analysis showing that MIP has a larger surface area , a larger pore volume, and a larger pore diameter than the MIP before extraction. The optimum conditions for the analysis of melamine using potentiometric sensor of nanoporous carbon paste/MIP electrode are the ratio of nanoporous carbon, MIP, and paraffin by 45:20:35 and the optimum pH value of 3-4. Results of melamine analysis using this sensor are the measurement range of 10-6 - 10-2 M, the detection limit is 9.51 x 10-7 M, the Nernst factor is 54.4 mV / decade, the accuracies of the concentration of 10-4 M and 10-3 M are respectively 106.1% and 104.3%, and this electrode is selective against melamine and is relatively undisturbed by Ca2 +, K +, Mg2 +, and Na + that are usually present in milk.