Capillary-based enzyme-linked immunosorbent assay for highly sensitive detection of thrombin-cleaved osteopontin in plasma

Fabrication and packaging of a mass-producible capillary-assembled microchip for simple and multiplexed bioassay

“…As an initial demonstration, we have successfully attained the multiplexed glycosidase enzyme assay. In addition to its use for enzyme activity assays, the CAs-CHIP-3G microdevice could also be used for other bioassays by integrating other capillary biosensors that we have developed previously for various analytes such as ions [27,28], metabolites [30,31], and proteins [37]. This inexpensive, reliable, and easy-to-use bioanalytical microdevice could be extended for colorimetric assay with the smartphone camera as the detector which has more potential for point-of-care or point-of-use applications.…”

“…We have developed various glass capillary biosensors to be integrated into CAs-CHIP, to measure various analytes such as proteins [25][26][27][28], ions [29,30], enzymes [30,31], and metabolites [32,33] Among many capillary biosensors developed, dry reagentrelease capillary (dRRC) which allows spontaneous dissolution of analytical reagents and selective reaction to give fluorescence response by sample introduction via capillary action, played an important role for the simplicity in capillary biosensor preparation and biosensing [30]. However, both the first (CAs-CHIP-1G) [23,30,31] and second (CAs-CHIIP-2G) [35] generations of CAs-CHIP requires the meticulous one-by-one capillary embedding onto a PDMS microchannel.…”

Advancements in Capillary-Assembled Microchip (CAs-CHIP) Development for Multiple Analyte Sensing and Microchip Electrophoresis

“…Furthermore, the development of a capillary sensor for highly sensitive detection of thrombin-cleaved osteopontin, a potential biomarker for ischemic stroke, in human plasma has been demonstrated. 46 Multi-step ELISA requires a longer analysis time because of the multiple washing steps and incubation intervals; therefore, we have made several efforts to decrease the number of steps by using the combination of RRC with antibodies immobilized on the inner surface of the capillary. [47][48] Despite these efforts, a purely single-step and robust immunosensing mechanism needs to be developed for real sample application for eventual integration with other biosensing capillaries in a single CAs-CHIP.…”

Fast and Single-step Fluorescence-based Competitive Bioassay Microdevice Combined PDMS Microchannel Arrays Separately Immobilizing Graphene Oxide-Analyte Conjugates and Fluorescently-labelled Receptor Proteins

“…However, long analysis time, high sample volume, and complicated operation are still recognized as the problems to be solved by many researchers in this field. [1][2][3][4] Recently, a large number of studies on technological developments of microsystems, microchemistry, and fully automated analytical systems have been reported in attempts to solve these problems. [5][6][7][8] However, simultaneously solving these problems is still challenging.…”