Objective: Molecularly Imprinted Polymer (MIP)-modified potentiometric sensors for histamine
(HIS) (as denoted as HIS sensor) have been developed.
Methods: The MIPs comprise HIS, Methacrylic Acid (MAA) and ethylene glycol dimethacrylate as
the template molecule, functional monomer and cross-linker, respectively. To examine the specificity
of the MIP to HIS, the MIP particles were prepared with varying ratios of HIS: MAA and the HIS
binding amount toward the MIP particles was determined by UV spectrophotometry. Furthermore, to
quantitatively determine the ability of MIP (H2M20) to HIS, a HIS sensor was measured using
Ag/AgCl as a reference electrode.
Results: MIP particles having a HIS:MAA of 2 mmol:20 mmol (MIP (H2M20)) had the largest HIS
binding amount among the MIP particles prepared. Additionally, MIP (H2M20) displayed a HIS
binding amount approximately two times larger than the corresponding non-imprinted polymer (NIP)
particles in the absence of template. The HIS sensor potential change increased as a function of HIS
concentration and exhibited a near-Nernstian response of −25.7 mV decade−1 over the HIS concentration
range of 1×10−5 to 1×10−4 mol L−1 with a limit of detection of 9.6×10−6 mol L−1. From the
Nernstian response value, it was observed that the HIS sensor could detect the di-protonated HIS
binding to the MIP. Conversely, when comparing at the same HIS concentration, the potential response
value of the sensors fabricated using NIP particles were significantly smaller than the values
of the corresponding HIS sensor.
Conclusion: The MIP-modified potentiometric sensors can potentially be employed as an analytical
method to quantitatively determine various analytes.