Electrochemiluminescence immunosensor based on ferrocene functionalized ZIF-8 quenching the electrochemiluminescence of Ru(bpy)32+-doped silica nanoparticles embodied N-butyl diethanolamine

Abstract

Herein, a quenching electrochemiluminescence (ECL) immunosensor was applied to detect procalcitonin (PCT) based on ferrocene carboxylic acid (Fca) quenching the ECL of Ru(bpy)32+. Co-reactant n-butyl diethanolamine and Ru(bpy)32+ co-doped in silica nanoparticles which grafted on g-C3N4 surface (RuSiNPs-g-C3N4) as luminophores. g-C3N4 could immobilize large amounts of RuSiNPs due to large specific surface area, besides, its electrical conductivity also contributed to enhance the ECL intensity. N-butyl diethanolamine serving as alternative co-reactant promoted ECL efficiency. Zeolitic Zn2+-imidazolate cross-linked frame-work (ZIF-8) were served as the supporter to immobilize more amounts of Fca, which could remarkably decrease the ECL signal. The quenching mechanism mainly because that the oxidation species of Fca could further react with the excited states of Ru(bpy)32+*. Under optimal experiment conditions, the proposed immunosensor presented a linear response range for detecting PCT from 5 pg mL−1 to 100 ng mL−1 with a detection limit of 0.85 pg mL−1 (S/N = 3). Furthermore, the proposed ECL immunosensor presented favorable specificity, good stability as well as excellent reproducibility, this strategy can offer a guiding significance in fundamental and clinical analysis of PCT.