Porphyrins as carriers in poly(vinyl chloride)-based membrane potentiometric sensors for histamine

Abstract

Iron(III) and manganese(III) tetraphenylporphyrins were explored as electroactive materials for preparing polymeric membrane-based sensors selective to histamine. The membranes, incorporating 30% poly(vinyl chloride) (PVC), 60% dioctyl phthalate (DOP), and 10% iron or manganese tetraphenylporphyrin, coated on the surface of graphite electrodes, exhibited near-Nernstian responses in the concentration range from 1 × 10^–6 to 1 × 10^–1 mol dm^–3 with detection limits of about 5 × 10^–7 mol dm^–3 histamine, and response times of <30 s. The electrodes show high selectivity towards histamine over several amino acids and common inorganic anions and can be used in a wide pH range. They were applied to the determination of histamine in synthetic serum samples.