DNA-Ag nanoclusters as fluorescence probe for turn-on aptamer sensor of small molecules

► A novel fluorescent aptamer sensor for small molecules was developed using DNA-Ag nanoclusters as probes. ► DNA-Ag nanoclusters were demonstrated as a cost-effective and turn-on fluorescent probe for the analysis of cocaine. ► The proposed design can be generally applied to other aptamers for turn-on detection of a broad range of analytes.