Streptococcal Protein G Enhances Antibody Binding to Platinum Sensor Surfaces

Photo-Electric Microbe Sensor is a patented biotechnology that detects microbes in aqueous solution by measuring the change in photo-voltage in response to UV light stimulation of a platinum (Pt) disk surface on an electrode before and after immunoprecipitation of microbes. This study aimed to increase the sensitivity of microbe detection by pre-adsorbing recombinant Streptococcal Protein G (PG), to the Pt sensor surface. Streptococcal PG binds the Fc region of mammalian IgG molecules and we investigated the association of PG to Pt and the resulting ability to tether antibodies to the Pt-PG surface. An ELISA protocol was optimized to detect the presence of mouse monoclonal antibodies tethered to Pt immunoaffinity disks, and to determine the recommended blocking solution and reagent concentrations. Our results demonstrate that PG binds to bare Pt, increases IgG affinity to the Pt surface following Superblock Buffer application, and together offers design-options for Pt-based sensor technologies.