Label-Free Detection of Salivary Pepsin Using Gold Nanoparticle/Polypyrrole Nanocoral Modified Screen-Printed Electrode.

摘要: Detection of salivary pepsin has been given attention as a new diagnostic tool for laryngopharyngeal reflux (LPR) disease, because saliva collection is non-invasive and relatively comfortable. In this study, we prepared polypyrrole nanocorals (PPNCs) on screen-printed carbon electrode (SPCE) by soft template synthesis method, using β-naphthalenesulfonic acid (NSA) (for short, PPNCs/SPCE). Gold nanoparticles (GNPs) were then decorated PPNCs/SPCE electrodeposition GNP/PPNCs/SPCE). To construct the immunosensor, antibody was immobilized GNP/PPNCs/SPCE. Next, citric applied to prevent non-specific binding change surface charge before incubation. Electrochemical stepwise characterization performed cyclic voltammetry, immunosensor response toward different concentrations measured differential pulsed voltammetry. As result, our electrochemical showed sensitive detection performance with linear range from 6.25 100 ng/mL high specificity pepsin, well low limit 2.2 ng/mL. Finally, quantified levels in samples LPR patients (n = 2), showing that results concordant those conventional ELISA method. Therefore, expect could be helpful preliminarily diagnosing through saliva.