BACKGROUND: @entity14782 ( @entity14782 ) is a powerful light scattering technique that can be used for sensitive immunoassay development and cell labeling. A major obstacle to using @entity14782 is the complexity of fabricating @entity14782 probes since they require nanoscale characterization and optical uniformity. The light scattering response of @entity14782 probes may also be modulated by the substrate used for @entity14782 analysis. A typical @entity14782 substrate such as quartz can be expensive. @entity852 is a cheaper substrate option but can decrease the @entity14782 response due to interfering Raman emission peaks and high background fluorescence. The goal of this research is to develop an optimized process for fabricating Raman-labeled nanoparticles for a @entity14782 -based immunoassay on a @entity852 substrate. RESULTS: We have developed a method for fabricating @entity14782 nanoparticle probes for use in a light scattering immunoassay on a @entity852 substrate. The light scattering profile of both spherical gold nanoparticle and gold nanorod @entity14782 probes were characterized using Raman spectroscopy and optical absorbance spectroscopy. The effects of substrate interference and autofluorescence were reduced by selecting a Raman reporter with a strong light scattering response in a spectral region where interfering substrate emission peaks are minimized. Both spherical gold nanoparticles and gold nanorods @entity14782 probes used in the immunoassay were detected at labeling concentrations in the low pM range. This analytical sensitivity falls within the typical dynamic range for direct labeling of cell-surface biomarkers using @entity14782 probes. CONCLUSION: @entity14782 nanoparticle probes were fabricated to produce a strong light scattering signal despite substrate interference. The optical extinction and inelastic light scattering of these probes was detected by optical absorbance spectroscopy and Raman spectroscopy, respectively. This immunoassay demonstrates the feasibility of analyzing strongly enhanced Raman signals on @entity852 , which is an inexpensive yet non-ideal Raman substrate. The assay sensitivity, which is in the low pM range, suggests that these @entity14782 probe particles could be used for Raman labeling of cell or tissue samples in a @entity852 tissue culture plate. With continued development, this approach could be used for direct labeling of multiple cell surface biomarkers on strongly interfering substrate platforms.

Rational design of Raman-labeled nanoparticles for a dual-modality, light scattering immunoassay on a XXXX substrate.

@entity852 :: ('MESH:D011137', 'Chemical') :: ['Polystyrene', 'polystyrene'] @entity14782 :: ('MESH:C564835', 'Disease') :: ['Surface-enhanced Raman scattering', 'SERS']
@entity852 :: (MESH:D011137,Chemical) :: ['polystyrene']
