The improved sensitive detection of C-reactive protein based on the chemiluminescence immunoassay by employing monodispersed PAA-Au/Fe3O4 nanoparticles and zwitterionic glycerophosphoryl choline

Nanocomposites are emerging complex nanoscale materials composed of different phases that have received considerable attention as a result of their widespread impact on a myriad of fields. Having said this, it is important to recognize that poor colloidal stabilities in physiological media and non-specific interactions with biology are key limitations prohibiting their successful translation into the development of practical technologies with real impact. Herein, PAA coated Au/Fe3O4 composite magnetic nanoparticles (NPs) with monodispersity and high biostability were engineered for the development of a highly sensitive C-reactive protein (CRP) chemiluminescence immunoassay (CLIA), based on the horseradish peroxidase (HRP)–luminol–H2O2 system. In addition, zwitterionic glycerophosphoryl choline (GPC) was employed as a co-blocking agent to reduce the nonspecific adsorption. This assay reports a limit of detection (LOD) of 2.5 pM with high reproducibility verified clinically and demonstrating improved progress towards translation into clinics.