High quality and facile DNA functionalized quantum dots (QDs) as efficient fluorescence nanomaterials are of great significance for bioimaging both in vitro and in vivo applications. Herein, we offer a strategy to synthesize DNA-functionalized Zn(2+) doped CdTe QDs (DNA-QDs) through a facile one-pot hydrothermal route. DNA is directly attached to the surface of QDs. The as-prepared QDs exhibit small size (3.85 ± 0.53 nm), high quantum yield (up to 80.5%), and excellent photostability. In addition, the toxicity of QDs has dropped considerably because of the Zn-doping and the existence of DNA. Furthermore, DNA has been designed as an aptamer specific for mucin 1 overexpressed in many cancer cells including lung adenocarcinoma. The aptamer-functionalized Zn(2+) doped CdTe QDs (aptamer-QDs) have been successfully applied in active tumor-targeted imaging in vitro and in vivo. A universal design of DNA for synthesis of Zn(2+) doped CdTe QDs could be extended to other target sequences. Owing to the abilities of specific recognition and the simple synthesis route, the applications of QDs will potentially be extended to biosensing and bioimaging.