A novel molecularly imprinted electrochemical sensor based on Prussian blue analogue generated by iron metal organic frameworks for highly sensitive detection of melamine

A novel electrochemical sensor based on molecularly imprinted polymer (MIP) and iron metal-organic frameworks was fabricated for highly sensitive detection of melamine (MEL) in this work. MIL-53(Fe), a kind of iron metal-organic frameworks, was prepared by a simple solvothermal method. The molecularly imprinted polymer films with specific recognition sites were synthesized by electropolymerization using methacrylic acid (MAA) as functional monomers interacted with MEL as templates. MIL-53(Fe) was characterized by XRD and FT-IR. The morphology of the MIP modified electrode was characterized by scanning electron microscopy. Under the optimal conditions, the molecularly imprinted electrochemical sensor (MIECS) shows a wide linear range of 10⁻¹¹ M to 10⁻⁶ M for MEL with a detection limit (3σ) as low as 8.21 × 10⁻¹² M. Moreover, the MIP sensor shows high selectivity for melamine, good reproducibility and stability. The MIECS has been applied to the real detection of melamine in liquid milk samples with satisfying results.