Development of cellulosic material-based microchannel device capable of fluorescence immunoassay of microsamples

• Published in: Analytical and bioanalytical chemistry Vol. 414; no. 11; pp. 3419 - 3428
• Main Authors: Shin, Jungchan, Kasama, Toshihiro, Miyake, Ryo
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-05-2022; Springer; Springer Nature B.V
• Subjects: Analysis; Analytical Chemistry; Biochemistry; Biomarkers; C-reactive protein; C-Reactive Protein - analysis; Cellophane; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Coefficient of variation; Enzyme-Linked Immunosorbent Assay; Fluorescence; Fluorescent Antibody Technique; Food Science; Humans; Immunoassay; Lab-On-A-Chip Devices; Laboratory Medicine; Medical wastes; Methods; Microchannels; Microfluidic Analytical Techniques; Microfluidics; Monitoring/Environmental Analysis; Photolithography; Reaction time; Reagents; Research Paper; Sensitivity; Substrates; Water resistance; Japan; Fluorescence sandwich immunoassay; Paper-based microchannel device; Human inflammation biomarker detection
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-022-03963-2

Microfluidic immunoassay devices are a promising technology that can quickly detect biomarkers with high sensitivity. Recently, many studies implementing this technology on paper substrates have been proposed for improving cost and user-friendliness. However, these studies have identified problems with the large volume of sample required, low sensitivity, and a lack of quantitative accuracy and precision. In this paper, we report a novel structure implemented as a cellulosic material-based microchannel device capable of quantitative immunoassay using small sample volumes. We fabricated microfluidic channels between a transparent cellophane film and water-resistant paper to facilitate loading of small-volume samples and reagents, with a 40-μm-wide immunoreaction matrix constructed in the center of the microchannel using highly precise photolithography. A fluorescence sandwich immunoassay for C-reactive protein (CRP) was successfully implemented that required only a 1-μL sample volume and a 20-min reaction time. We confirmed that the limit of detection of the device was 10–20 ng/mL with a coefficient of variation under 5.6%, which is a performance level comparable to conventional plastic-based human CRP enzyme-linked immunosorbent assay (ELISA) kits. We expect that such devices will lead to the elimination of large amounts of medical waste from the use of ubiquitous diagnostics, a result that is consistent with environmental sustainability goals.