Synthesis of nano‐sized hydrogen phosphate‐imprinted polymer in acetonitrile/water mixture and its use as a recognition element of hydrogen phosphate selective all‐solid state potentiometric electrode

Herein, a new recipe is introduced for the preparation of hydrogen phosphate ion‐imprinted polymer nanoparticles (nano‐IIP) in acetonitrile/water (63.5:36.5) using phosphoric acid as the template. The nano‐IIP obtained was used as the recognition element of a carbon paste potentiometric sensor. The IIP electrode showed a Nernstian response to hydrogen phosphate anion; whereas, the non‐imprinted polymer (NIP)‐based electrode had no considerable sensitivity to the anion. The presence of both methacrylic acid and vinyl pyridine in the IIP structure, as well as optimization of the functional monomers‐template proportion, was found to be important to observe the sensing capability of the IIP electrode. The nano‐IIP electrode showed a dynamic linear range of 1 × 10^?5‐1 × 10^?1 mol L‐1, Nernstian slope of 30.6 ± (0.5) mV decade ^?1, response time of 25 seconds, and detection limit of 4.0 × 10^?6 mol L^?1. The utility of the electrodes was checked by potentiometric titration of hydrogen phosphate with La³⁺ solution.