An aptamer-functionalized gold nanoparticle biosensor for the detection of prion protein

Prions are a special class of pathogens that cause a number of fatal neurodegenerative diseases in mammals. This paper presents a very simple and convenient biosensor for detecting prion protein, in which a prion protein aptamer was used as the molecular recognition group and gold nanoparticles were used as the signal report group. Binding of the target molecular prion protein resulted in the enhancement of resonance light scattering (RLS) by the gold nanoparticles. A linear relationship was then identified between the enhanced RLS intensity and the concentration of prion protein in the range 0.2 to 50 nmol L−1, with a limit of detection of 0.07 nmol L−1 (3σ). The biosensor has very good selectivity for prion protein without interference by coexisting proteins, amino acids or metal ions. This “aptasensor” offers a rapid, selective and sensitive route for prion protein detection and has good potential for use in practical applications.