Highly specific colorimetric detection of DNA oxidation biomarker using gold nanoparticle/triplex DNA conjugates

The gold nanoparticle/triplex DNA conjugates contained a pre-organized cavity that can bind 8-oxoGua with strong affinity and excellent selectivity over other nucleobases. Nanoparticle assemblies interconnected with DNA triple helices bound with 8-oxoGua show much sharper and significantly higher melting temperatures than the analogous free DNA triplex. By simply incubating our sensor with a urine sample, 8-oxoGua can be detected colorimetrically at submicromolar concentrations with a UV-vis spectrometer or even by naked eyes.143