We evaluated optical pickup ELISA with an original microfluidic disk that contains eight radially arranged channels, which enable semi-automatic sample loading and washing. This disk-shaped chip composed of acrylic plates was fabricated by CO2 laser machining and capture antibodies were immobilized in the channels. After the immunoreaction with antigens and enzyme-linked secondary antibodies, an enzyme-catalyzed nanoaggregation of o-phenylenediamine was detected by measuring the reflectivity change of a laser beam focused in the channel. The assay of C-reactive protein (CRP) was successfully performed in a short amount of time (approximately 20 min from CRP loading). The limit of detection was determined to be 2 ng mL-1, which is more sensitive as compared with conventional ELISA using microplates.
Yoshikawa, H., Yoshinaga, M., & Tamiya, E. (2018). An optical pickup enzyme-linked immunosorbent assay (ELISA) with a microfluidic disk. RSC Advances, 8(26), 14510–14514. https://doi.org/10.1039/c8ra01149d