Direct quantification of γ-globulin in human blood serum by resonance light scattering techniques without separation of human serum albumin Original Research Article

We describe the preparation and characterization of functionalized nano-PbS. The functionalized nanoparticles are water-soluble. Reaction of mercaptoacetic acid functionalized nano-PbS with γ-globulin (γ-IgG) results in an enhanced resonance light scattering (RLS) at 385 nm. Based on this, a new direct quantitative method for γ-globulin in blood serum samples without separation of human serum albumin is established. Under optimal conditions, the enhanced RLS intensity is in proportion to the γ-IgG concentration in the range 10–500 ng ml−1. The 3σ limit of detection is 2.75 ng ml−1. The contents of γ-IgG in blood serum samples were determined with a recovery of 97–104% and R.S.D. of 1.5–2.1% (n=6). This method proved to be very sensitive, rapid, simple and tolerant of most interfering substances.