15 nm nanogold was used to label goat anti-human ceruloplasmin (GCP) to obtain an immunonaogold resonance scattering (RS) probe (AuGCP) for ceruloplasmin. In the pH 7.8 citric acid-Na2HPO4 buffer solution, the immunoreaction between nanogold-labeled goat anti-human ceruloplasmin (AuGCP) and CP took place to form a nanogold-labeled immune complex. After centrifugation, the AuGCP in the centrifugal solutions could be used as catalyst for the reaction between Fehling reagent and glucose. The product of Cu2O particles has the strongest resonance scattering (RS) peak at 620 nm. Under the selected conditions, the decreased intensity ΔI620 nm is proportional to CP concentration (cCP) from 0.18 to 45 ng/mL, with a regression equation of ΔI620 nm＝2.27cCP＋5.05, with a correlation coefficient of 0.9940, and a detection limit of 0.14 ng/mL CP. This simple and sensitive RS assay was applied to determination of CP in human plasma with satisfactory results.

Key words: ceruloplasmin, immunonanogold catalysis, Cu2O particle, glucose, resonance scattering spectral assay