Development of an electrochemiluminescence immunosensor for diagnosis of cystic echinococcosis using a BSA-AuNCs-chitosan-AgNPs-luminol nanocomposite

Cystic echinococcosis (CE) is a serious zoonotic disease that affects humans and animals worldwide and is caused by the parasite Echinococcus granulosus , which lives in dogs as its final host. Detecting the disease early is vital to prevent serious health problems. However, in the early stages of infection, the body produces only very low levels of antibodies against the parasite. Because of this, routine laboratory tests often struggle to identify the infection at this stage. In this study, we designed a highly sensitive electrochemiluminescence (ECL) immunosensor to detect CE. To amplify the detection signal, we used chitosan–gold nanoclusters decorated with silver nanoparticles (CS-AuNCs-AgNPs), together with a luminol/H 2 O 2 ECL system. These nanomaterials were rapidly and uniformly deposited on the electrode surface using chronoamperometry technique, creating a stable nanofilm in just 2 min. We then immobilized antigen B on the electrode as a biological recognition layer to capture CE-specific antibodies. When serum from an experimentally infected mouse was applied, binding of the antibodies to antigen B reduced the ECL signal due to steric hindrance serving as our detection indicator. The successful assembly of nanomaterials on the electrode surface was confirmed using SEM, EDX, and dot-plot analyses. Overall, this work presents a sensitive, rapid, and reproducible platform that holds strong potential for early clinical detection of cystic echinococcosis. • A novel ECL immunosensor was developed using a BSA–Au nanocluster–chitosan–AgNP–luminol nanocomposite for sensitive detection of cystic echinococcosis (CE). • Rapid and uniform electrode nanofilm formation was achieved via chronoamperometry within 2 minutes, enabling a stable and reproducible sensing interface. • Synergistic nanocomposite architecture (BSA-AuNCs/AgNPs) significantly enhanced luminol ECL response, allowing detection of CE-specific antibodies at early infection stages.