Development of Immunochromatographic Assay of the Anti-Mullerian Hormone by Surface-Enhanced Raman Scattering Using Bimetallic Nanoparticles

The use of surface-enhanced Raman spectroscopy (SERS) in immunochromatographic assay (ICA) supports integration of the rapidity, simplicity, and specificity of the immunoassay with high sensitivity and accuracy of SERS registration. An immunochromatographic test system has been developed for detection of the anti-Müllerian hormone (AMH), a marker of ovarian reserve in women of reproductive age. ICA has been implemented in a sandwich format, which facilitates the interaction between the AMH molecules in the tested sample and a pair of monoclonal antibodies that recognise different antigen epitopes. This interaction results in the formation of AMH-labeled antibody complexes (where the antibody is immobilized on the membrane of the immunochromatographic test strip). We have used bimetallic gold–silver core-shell nanoparticles modified with a SERS-active reporter molecule to label antibodies. We have evaluated the size characteristics of the nanoparticles and selected the optimal conditions for their conjugation with antibodies. ICA has been performed under conditions that ensure the achievement of the minimum AMH detection limit. The developed ICA-SERS system has a detection limit of 0.15 ng/mL and a working range of 4.7–29.5 ng/mL satisfying practical diagnostic requirements. The analytical system has been applied successfully to testing blood serum.