Highly Selective, Naked-Eye, and Trace Discrimination between Perfect-Match and Mismatch Sequences Using a Plasmonic Nanoplatform

A plasmonic nanoplatform to perform an enzyme-free, naked-eye, and trace discrimination of single-base mutation from fully matched sequence is reported. The nanoplatform showed great potential to enhance catalytic hairpin assembly (CHA) amplification efficiency and biocatalytic activity of hemin/G-quadruplex (DNAzyme). When human immunodeficiency virus (HIV) DNA biomarker was used as the model analyst, a naked-eye detection with high selectivity and high sensitivity down to 10–17 M in whole serum was achieved by observing red-to-blue color change. Single-base mismatch and two-base mismatch were detected at the low concentrations of 10–11 and 10–8 M, respectively. The naked-eye detection based on the enzyme-free plasmonic nanoplatform is expected to have potential applications ranging from quick detection and early diagnostics to point-of-care research.