title: A stacking flow immunoassay for the detection of dengue-specific immunoglobulins in salivary fluid.
abstract: Paper-based immunoassays, usually in the form of lateral flow tests, are currently the standard platform for home diagnostics. However, conventional lateral tests are often complicated by severe non-specific adsorption of detector particles when applied to test samples containing salivary fluid. It is believed that a high concentration of proteinaceous substances in salivary fluid causes particle aggregation and adhesion. In this study, we developed a stacking flow platform for single-step detection of a target antibody in salivary fluid. Stacking flow circumvents the need for separate sample pre-treatments, such as filtration or centrifugation, which are often required prior to testing saliva samples using paper-based immunoassays. This is achieved by guiding the samples and reagents to the test strip through different paths. By doing so, salivary substances that interfere with the particle-based sensing system are removed before they come into contact with the detection reagents, which greatly reduces the background. In addition, the stacking flow configuration enables uniform flow with a unique flow regulator, which leads to even test lines with good quantification capability, enabling the detection of ~20 ng mL(-1) α-fetoprotein in the serum. We have successfully applied the stacking flow device to detect dengue-specific immunoglobulins that are present in salivary fluid.
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669. jyying@ibn.a-star.edu.sg.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jianhao
authors.initials: J
authors.lastname: Bai
authors.forename: Jackie Y
authors.initials: JY
authors.lastname: Ying
mesh_terms: D003716:Dengue Virus / Q000276:immunology*; D004867:Equipment Design; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D007074:Immunoglobulin G / Q000032:analysis / Q000276:immunology; D007136:Immunoglobulins / Q000032:analysis* / Q000276:immunology; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D012463:Saliva / Q000737:chemistry*; D013045:Species Specificity
chemical_list: D007074:Immunoglobulin G; D007136:Immunoglobulins