Microarray based Raman spectroscopic detection with gold nanoparticle probes

In this paper, we developed a novel microarray based surface-enhanced Raman spectroscopic (SERS) assay for detection of peptide and protein interaction by attachment of gold nanoparticles followed by silver deposition for signal enhancement. The attachment of the gold nanoparticles is achieved by standard avidin-biotin chemistry. The well-known biomolecular recognition systems, IgG with protein A and biotin with avidin, were chosen here to establish the SERS assay. In the spectroscopic assay, peptide is detected down to a limit of 10 fg on the microarray spots. And recognition of standard proteins (protein A and IgG) down to 0.1 mu g/mL for proteins in solution and 100 fg for proteins on the microarray spots are also demonstrated.