Rapid and Selective Determination of Folate Receptor α with Sensitive Resonance Rayleigh Scattering Signal

A rapid, simple, and novel method for folate receptor α (FR α ) determination is reported here. A probe of gold nanoparticles (Au NPs) modified with anti-FR α antibody was synthesized under the optimized conditions first. The antibody-modified Au NPs would aggregate when FR α was added to the probe for the specific interaction between antibody and antigen, resulting in the enhancement of resonance Rayleigh scattering (RRS) intensity. There is a linear relationship between the change of RRS intensity (Δ I RRS ) and the concentration of FR α , with the detecting range of 0.50–37.50 ng·mL −1 and the limit of determination of 0.05 ng·mL −1 . The determination of FR α in serum samples was realized with the advantages of high selectivity, high sensitivity, and easy operation.