Engineering a Novel Inorganic/Organic Chimeric Biosensor: The Supersensitive Detection and Quantitative Analysis of Cell Biomarkers

Abstract

In this study, we propose the use of a novel inorganic/organic chimeric biosensor to detect and quantify cellular membrane biomarkers. Using a bacterial expression system, we engineered human ferritin heavy chain subunits to consist of linker proteins. The modified human ferritin subunits self-assembled to form spherical nanoparticles, onto which water-solubilized quantum dots and an antibody specific for a pancreatic cancer cell biomarker were conjugated via the extraluminal surface linker proteins. Membrane biomarkers mesothelin and claudin-4 from Panc-1 and Capan-1, respectively, were designated as model targets to assess the recognition and quantitative capabilities of the chimeric biosensor. Meanwhile, fluorescent antibodies specific for mesothelin and claudin-4 were used as a control. The fluorescence from the membrane biomarkers was quantified by intensity to assess the quantity of biomarkers. In conclusion, we successfully used an inorganic/organic chimeric biosensor to not only detect, but also quantify cellular biomarkers.