A new and selective and sensitive nanogold-labeled immunoresoance scattering spectral assay for trace prealbumin

A gold-labeled immunoresonance scattering spectral probe for trace prealbumin (PA) was prepared by using gold nanoparticles in size of 9.0nm to label goat anti-human prealbumin polyclonal antibody. The immune reaction between the gold-labeled antibody and prealbumin took place in pH 7.6 Na2HPO4-NaH2PO4 buffer solution. In the presence of polyethylene glycol PEG-10000, the labeled gold nanoparticles were released and aggregated which brought the resonance scattering intensity (I-RS) at 580 nm to enhance greatly. The Delta I-RS is proportional to the prealbumin concentration in the range from 16.67 to 666.67 ng/mL, with a detection limit of 4.1 ng/mL. This simple, sensitive and selective assay was applied to determination of prealbumin in human plasma, with satisfactory results. (c) 2007 Published by Elsevier B.V.