Antibody-Based Assays for Phenotyping of Extracellular Vesicles

Figure 5

Schematic view of the nPLEX platform. Antibodies are immobilized on the nPLEX chip (chip with periodic nanoholes patterned in a gold film) and EVs are introduced to the chip via a 12-channel fluidic cell placed on top of the nPLEX chip. EVs are captured based on the presence of surface antigens. The optical path from the laser passes through the nPLEX chip which is located on top of the imager and the light intensities transmitted through the nanoholes arrays are recorded in parallel by the complementary metal oxide semiconductor (CMOS) imager. Light illumination to the nanohole array excites strong electromagnetic fields, which lead to optical transmission. EV binding to the nanohole surface (via antibodies) can redshift the optical transmission peaks, which can be monitored by measuring intensity changes at fixed wavelength (658 nm).