title: Power-free microchip immunoassay of PSA in human serum for point-of-care testing.
abstract: For point-of-care testing (POCT), a sandwich-typed immunoassay on poly(dimethylsiloxane) (PDMS) microfluidic chips was developed by employing two original technologies: a power-free microchip and laminar flow-assisted dendritic amplification (LFDA). Sequential injection of reagents of immunoassay was carried out by the power-free microchip. In addition, for the amplification of a fluorescent signal, LFDA exploited the interaction between FITC-labeled streptavidin and biotinylated anti-streptavidin on the interface of the two streams of laminar flow during the sequential injection of the reagents of the immunoassay. The microfluidic immunoassay was finished within 21 min with a sample volume of 500 nL. The calibration curve of a quantitative analysis satisfied the concentration range of the cut-off values of prostate-specific antigen (PSA) in serum. The limit of detection (LOD) reached 520 pg/mL (16 pM) of PSA in human female serum. We believe that this microfluidic immunoassay and device are promising for POCT.
authors.affiliation: Bioengineering Laboratory, RIKEN, Wako, Saitama, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Okada
authors.forename: Kazuo
authors.initials: K
authors.lastname: Hosokawa
authors.forename: Mizuo
authors.initials: M
authors.lastname: Maeda
mesh_terms: D000906:Antibodies / Q000032:analysis / Q000276:immunology; D019921:Biotinylation / Q000379:methods; D002097:C-Reactive Protein / Q000737:chemistry; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D005260:Female; D005455:Fluorescent Antibody Technique / Q000379:methods*; D005456:Fluorescent Dyes / Q000032:analysis; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008297:Male; D046208:Microchip Analytical Procedures / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000379:methods; D019095:Point-of-Care Systems; D017430:Prostate-Specific Antigen / Q000032:analysis* / Q000276:immunology*; D015203:Reproducibility of Results; D044967:Serum / Q000737:chemistry / Q000276:immunology; D019809:Streptavidin / Q000276:immunology
chemical_list: D000906:Antibodies; D004129:Dimethylpolysiloxanes; D005456:Fluorescent Dyes; D002097:C-Reactive Protein; D019809:Streptavidin; D017430:Prostate-Specific Antigen