Extruded microfluidic immunoassays

This paper reports the miniaturisation of sandwich enzyme-linked immunosorbent assays (ELISA) using a meltextruded fluoropolymer MicroCapillary Film (MCF). A prototype 8-channel*10-microcapillaries device was used for quantitative detection a range of human biomarkers in 30 mm long fluoropolymer MCF strips. This represents a novel combination of ultra-low cost plastic microfluidic strips, low-cost optical detection, short incubation times, pre-loaded reagents and sequential fluid aspiration based on disposable plastic syringes. The observed limit of detection (LOD) was ∼lng/ml for PSA, and 10-60pg/ml for IL-lbeta, IL-6 and IL-12 inflammatory cytokines, typically with CVs ≤ 10% which is comparable with performance of optimised colorimetric microwell-based ELISA.