Enzyme-free amplified SERS immunoassay for the ultrasensitive detection of disease biomarkers.

We developed a novel enzyme-free amplified SERS immunoassay by combining silver nanoparticle (AgNP)-linked immunoreaction and SERS transduction for the detection of disease biomarkers. As a proof of concept, our method was successfully illustrated with the disease biomarker α-fetoprotein with the detection limit of 3.3  ×  10-13 g mL-1 and a double-blind experiment consisting of tens of serum samples was performed to confirm its reliability.