One-step gold nanoparticle size-shift assay using synthetic binding proteins and dynamic light scattering

Gold nanoparticle (AuNPs) coupled dynamic light scattering (DLS) is a biosensing technique combining the properties of AuNPs with analyte recognition to produce an easy-to-use analytical tool. The principle assay immobilize bioreceptors specific target onto nanobiosensors. When added system, binding protein immobilized leads size shift functionalised AuNPs. This in can be quantified by DLS. It has proven effective detecting multiple analytes such as metal ions, small chemicals and macromolecules. Previously, antibodies (Abs) have been used this technique. However, here we report use synthetic proteins, termed Affimer reagents, bioreceptors. Anti-myoglobin Affimers were isolated phage display characterized ELISA surface plasmon resonance (SPR). Five showed strong myoglobin nanobiosensors for DLS assay. could selectively detect limit detection 554 fM. AuNP concentration tested proved important factors