Analytical Sciences

Abstract − Analytical Sciences, 33(10), 1111 (2017).

Immunoassay for Human IgG Using Antibody-functionalized Silver Nanoparticles
Daniela M. BATISTELA, Cassius V. STEVANI, and Renato S. FREIRE
Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo (USP), Av. Prof. Lineu Prestes, 748, 05508-000, São Paulo/SP, Brazil
A simple colorimetric immunoassay for quantification of human immunoglobulin G (hIgG) is herein described. The assay is based on the aggregation inhibition of silver nanoparticles (AgNP) functionalized with hIgG antibody (anti-hIgG) on the surface. The aggregation is measured in terms of attenuance values ratio at 400 and 530 nm (A400/A530). A linear response between A400/A530 and hIgG concentration is observed in the range 25 – 200 ng mL−1, and the detection limit is estimated as 11 ng mL−1 hIgG.