A strategy for constructing sensitive and renewable molecularly imprinted electrochemical sensors for melamine...

A novel strategy for preparing highly sensitive and easily renewable molecularly imprinted polymer (MIP) sensors was proposed. Using melamine (MA) as the template molecule, MIP particles were synthesized and embedded in a solid paraffin carbon paste to prepare the MIP sensor. MA was indirectly determined from the competition between the reactions of MA and horseradish peroxidase-labeled MA (MA-HRP) with the vacant cavities. The detection signals were amplified because of enzymatic reaction to the H(2)O(2) catalytic oxidation. Sensitivity was markedly improved. Sensor renewal was achieved by a simple mechanical polishing of the sensitive film. The linear range for MA detection was 0.005-1 μmol L(-1) and the detection limit was 0.7 nmol L(-1). The molecularly imprinted solid paraffin carbon paste sensor was used for MA detection in milk samples.