Fig. 4: Digital vs. analog plasmonic fluor-linked immunosorbent assay.
From: Plasmon-enhanced bioassay for amplification-free detection and quantification of SARS-CoV-2 RNA
Plots showing dose-dependent response, LOD and LLOQ analyzed in the digital (red) and analog (black) formats for SARS-CoV-2 RNA. A For ORF1ab, the LOD and LLOQ were found to be 16 aM and 74.6 aM for analog assay, and 1.2 aM and 8.7 aM for digital assay, respectively. B For N gene, the LOD and LLOQ were found to be 23.4 aM and 59 aM for analog assay, and 0.8 aM and 7.5 aM for digital assay, respectively. C For mixture of ORF1ab & N genes, the LOD and LLOQ were found to be 2.9 aM and 18.4 aM for analog assay, and 0.3 aM and 2.9 aM for digital assay, respectively. Technical replicates with n = 2, and data is presented as mean + s.d. D Representative epifluorescence images corresponding to different concentrations of ORF1ab RNA, showing the progressive increase in the number of plasmonic-fluors with the concentration of the target RNA. Black arrows indicate LOD, and blue arrows indicate LLOQ. Data points corresponding to blanks are included as the lowest concentration in the plots.
