Nanogold particle-enhanced oriented adsorption of antibody fragments for immunosensing platforms

A general design strategy for immunosensing platforms has been proposed on the basis of Nanogold particle-enhanced oriented adsorption of antibody fragments. Quartz crystal microbalance (QCM) as a model transducer was fabricated with plasma-polymerized film (PPF) of n-butyl amine and then with nanogold particles resulting in a PPF-nanogold adsorption procedure for half-IgG fragments obtained by reduction of intact immunoglobulin (IgG). Thermodynamic studies reveal that the proposed procedure is superior to the traditional oriented ones in that it created immunosurface of increased antibody surface density (amount) and antigen binding constants. Sensors produced according to the new immobilization procedure exhibit better immunosensing performances including high sensitivity, fast response rate, and favorable operational stability etc. This Nanogold particle-enhanced immobilization technique may be tailored as a promising alternative for various immunosensing platforms in solid-phase immunoassay and affinity chromatography.