SERS Immunoassay Using Microcontact Printing for Application of Sensitive Biosensors

Abstract

E-mail: ymjung@kangwon.ac.krReceived August 18, 2011, Accepted October 9, 2011We introduced a promising patterned substrate by using a microcontact printing method that can be used forSERS immunoassays based on antigen-antibody binding. SERS spectrum of the Raman reporter with antibody,which is rhodamine 6G (R6G) adsorbed on colloidal gold nanoparticles, was observed only for the surfaces inwhich prostate-specific antigen (PSA) is present on the substrate that is attached to an immobilized layer ofantibody on the gold nanoparticles layer of the patterned substrate. Raman mapping images clearly showed thatthe antibodies on the Raman reporter were successfully and selectively conjugated with the antigen on thepatterned substrate. This method could be potentially extended to multi-protein detections and ultrasensitivebiosensors.Key Words : Surface-enhanced raman scattering (SERS), Immunoassay, Microcontact printing, Gold nano-paticles, BiosensorsIntroductionSurface-enhanced Raman scattering (SERS) spectroscopy,in which the scattering cross-sections are dramatically en-hanced for molecules adsorbed on metallic nanostructures,has recently received considerable attention as a powerfulanalytical tool in ultrasensitive chemical analysis, biologicalimaging, and material studies.