Figure 2 | Scientific Reports

Figure 2

From: A handheld platform for target protein detection and quantification using disposable nanopore strips

Figure 2

Selective detection of HIV antibody 447-52D using a single nanopore and an engineered detection reagent. (a) Contrasting molecular cartoons and recorded nanopore event signatures for (i) DNA alone, (ii) DNA/PNA-peptide detection reagent, (iii) DNA/PNA (sans peptide) with antibody and (iv) detection reagent bound by antibody. Each reagent (i–iv) was measured sequentially on the same 27 nm diameter pore. In between each reagent, the nanopore was flushed with clean buffer for 5 minutes. The number of events N and recording periods were: (i) N = 332 in 16 min, (ii) N = 434 in 13 min, (iii) N = 353 in 18 min, (iv) N = 441 in 19 min. (b) EMSA and nanopore event plots display consistent trends for (i–iv). Unlabelled lanes were not analyzed on the nanopore in this study. The gel upper band that is indicative of full complex (DNA/PNA-peptide/antibody) matches the pronounced increase in nanopore events with larger max δG values. In particular, while less than 2% of events for (i–iii) are above max δG = 3 nS, the fraction increases to 23% for full complex (iv), a trend used for positive detection with 99% confidence as described in the main text. The variable Q denotes the fraction of events tagged as target positive, with 99% confidence interval \(2.58\sqrt{Q\mathrm{(1}-Q)/N}\).

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