Detecting the adulteration of antihypertensive health food using G-insertion enhanced fluorescent DNA-AgNCs

In this work, a new phenomenon was found that the insertion of guanine (G) bases into the cytosine (C)-rich DNA could endow enhanced fluorescence intensity of DNA-templated silver nanoclusters (DNA-AgNCs). This could be another important finding after Yeh's report that DNA-AgNCs can be greatly enhanced when placed in proximity to G-rich bases and, a supplementary proof for the understanding of G&C roles in the synthesis of DNA-AgNCs. A sequence (C(6)G(5)G(6)) was selected for the synthesis of DNA-AgNCs of quantum yield 28%. The AgNCs were employed as a visual and facile probe for the sensitive detection of captopril in antihypertensive health food. This detection strategy showed good linear response to captopril with applicability in complex matrices of real samples.