Peptide-Based Plasmon-Enhanced Spectroscopic Immunoassay to Detect Immunity Against Cytomegalovirus.

Sensors to monitor the immune status of an individual play a crucial role in understanding the acquired immunity or signs of a latent infection. Such sensors can be an effective tool to manage infection and to design treatment options in vulnerable populations. We demonstrate here highly sensitive detection of acquired immunity to Cytomegalovirus CMV by detection of anti-CMV antibodies using plasmon-enhanced fluorescence (PEF). The PEF sensors leverage plasmonic enhancement from a high density of intense electromagnetic hotspots in self-assembly-derived gold nanopillar arrays. Comparing PEF assays with assays on a planar surface plasmon resonance sensor shows the PEF sensors to be sensitive to a small fraction of the antibodies on the surface. The detection scheme deploys peptide monolayers with specific affinity to anti-CMV antibodies to capture them onto the sensor surfaces. The results of the assay on the PEF sensor reveal high promise for sensors with miniaturized sensing footprints, ease of spatial multiplexing, high sensitivity, and quick response times. The developments are readily applicable to a range of other diagnostic contexts where peptide-protein interactions and self-assembly-derived PEF sensors can be leveraged.