Biocompatible protein nanogels as robust signal labels for persistent chemiluminescence immunoassays

Nanostructured materials with elegant properties have promising potentials in chemiluminescence (CL) immunoassay . However, the robust preparation of such nanomaterials is still challenging. In this work, biocompatible and easily prepared gelatin/horseradish peroxidase (Gel/HRP) nanogels were exploited as signal labels for chemiluminescence immunoassays. The catalytic property of HRP was well retained and the stability was improved after the incorporation into nanogels. The prepared protein nanogels show enhanced and glow-type luminescence behaviors in luminol-H 2 O 2 CL system. Persistent and sensitive CL immunoassay for CEA were constructed using Gel/HRP nanogels as signal labels. A wide linear response range from 0.01 to 100 ng/mL was obtained with the limit of detection was 3.39 pg/mL (S/N = 3).