Novel multifunctional molecular recognition elements based on molecularly imprinted poly (aniline-co-itaconic acid) composite thin film for melamine electrochemical detection

Abstract

The combination of copolymerization and molecularly imprinting technology provides functional materials with improved properties and can enhance the number of binding sites than the individual monomer. In this work, molecularly imprinted poly (aniline-co-itaconic acid) (MI-PANI-PIA) composite thin film was synthesized on glassy carbon electrode (GCE) by using an in-situ electropolymerization method using melamine (MA) as a template. The formation of the thin film was monitored by electrochemical methods and characterized by Fourier transform infrared (FTIR) spectrophotometry and scanning electron microscopy (SEM). Solvent extraction of the template generated the binding cavities in the polymer matrix which fit the target in size, shape and functionality. After the rebinding of MA, the proposed sensor shows a linear range between 0.25 × 10−9 M to 100 × 10−9 M, limit of quantification (LOQ) of 5.98 × 10−11 M and limit of detection (LOD) of 1.79 × 10−11 M respectively. The composite film showed high affinity towards MA through multiple non-covalent interactions, good reproducibility and stability with RSD 4.02% and 4.67% respectively. The developed sensor has an interesting potential for real sample testing applications with good recovery ranging from 95.87% to 101.5%. The new sensing composite material has good sensitivity and selectivity due to the synergistic effects of multi-functionality from the two polymers, porous thin film and imprinting effect. To this end, the MI-PANI-PIA can be regarded as a potential functional material for the chemical sensor development in future.