Fiber based enzyme-linked immunosorbent assay for C-reactive protein

Development of new enzyme-linked immunosorbent assays (ELISA) is essential, considering the improvement required in assay performance with regard to traditional ELISA. Herein, fiber based ELISAs with high sensitivity were developed from different platforms, namely electrospun poly-L-lactic acid (PLLA) and cellulose acetate (CA) nanofibers; and microfibers of commercial sanitary cotton swabs. The ability of the developed fiber based ELISAs to detect C-reactive protein (CRP) as a cardiac biomarker was successfully tested. The limit of detection (LOD) was measured at 13 pg/ml, 53 pg/ml and 27.32 pg/ml for PLLA, CA nanofibers and cotton microfiber based platform, respectively and the LODs were lower than that of the conventional ELISA. Additionally, the incubation process time was reduced to 150 min for PLLA and CA electrospun nanofibers; and 90 min for cotton swab ELISA, compared to conventional ELISA test (315 min). Moreover, the results of the colorimetric CRP analysis obtained from cotton swab-based ELISA showed its effectiveness as a low cost and sensitive point of care device with ability of monitoring the salivary CRP level for detection of cardiac vascular diseases.