Potentiometric analysis of sialic acid with flexible carbon cloth based on boronate affinity and molecularly imprinted polymers

An electrochemical platform was proposed for highly sensitive and selective analysis of sialic acid based on molecularly imprinted polymers (MIPs), which was electropolymerized with monomer molecules of 3-aminophenylboronic acid (ABA) on a cloth carbon (CC) electrode in the presence of template molecules. The fabricated sensor, named as PABA/CC-based MIP electrode, could be used for detection of sialic acid because a reversible and covalent boronic acid-diol binding was sensitive to the electrochemical potential of the prepared sensor. The utilization of CC film as the substrate could improve the sensitivity due to its good electrical conductivity and large surface area. Under optimized conditions, a good relationship between the potential change and the concentration of sialic acid was obtained in the range of 40 μM to 440 μM with a detection limit of 0.5 μM. The resulting MIP sensor also displayed good selectivity, reproducibility and stability. Moreover, this sensor was successfully applied for the evaluation of the sialic acid level in infant formulas.