Protoporphyrin IX Based All-Solid-State Ion-Selective Electrodes for Choline Determination In Vitro

Protoporphyrin IX-based all-solid-state choline (Ch) ion-selective electrodes (ISEs) were fabricated and characterized. Poly (3,4-ethylene dioxythiophene) doped with poly (styrene sulfonate) (PEDOT/PSS) functioning as an ion-to-electron transducer was electropolymerized on the gold wire (0.5 mm diameter). The conductive polymer covered a Ch selective membrane containing protoporphyrin IX ionophore, which exhibited lower detection limit of 0.49 μM potentiometric method. sensor performed wide linear range from 1 to mM, fast response time less than 5 s, decent selectivity common inorganic organic ions in human body. Characteristics such pH temperature stability, life span, reproducibility repeatability also investigated be satisfied. With background artificial cerebrospinal fluid, recovery rate 10−5 M solution measured by standard addition method, revealing potential for biological application.