Figure 6: Sensitivity and selectivity studies. For (a) and (b): Serially-diluted synthetic dengue DNA was added (from left: 10-4, 10-5, 10-6, 10-7, 10-8, and 10-9 M dengue DNA) onto the AuNP-DNA mixture and added to a test strip with striped capture probe in PBS for (a) and healthy human blood in (b). Selectivity is studied in (c) where a 10-4 M mismatch DNA is added instead of dengue DNA in PBS and blood matrix. Both show a red band indicating a negative result. (d) shows a graph of the intensity of the red bands in (a) and (b).