Development of high-performance immuno-pillar devices: Improvement of antibody-immobilized solid support

In order to realize ultra-early diagnosis of disease in practical applications, we have fabricated next-generation immuno-pillar devices with higher sensitivity. In the newly developed devices, capture antibodies were immobilized on affinity beads based on chemical bonding, while in the previous-generation ones, polystyrene beads were used for physical adsorption-based immobilization. To evaluate the sensitivity of the next-generation immuno-pillar device, we quantitatively analyzed C-reactive protein (CRP). The limit of detection was estimated to be 0.1 ng mL^-1 (total assay time, 23 min), which was twoorders of magnitude lower than that obtained by using the previous-generation immuno-pillar device, and was low enough to perform the CRP test. In addition, we investigated the storage stability of the immuno-pillar device, and confirmed that the device can retain its performance for over 9 months.