A DNA–Au nanomachine activated by dual types of biomarkers for multi-site imaging and gene silencing† Yanmei Zhou, a Zhaoge Li,a Tian Wu,a Juan Ning,a Guizhen Hua and Yamin Nie *a Abstract A programmed DNA–Au nanomachine has been constructed to achieve in situ imaging of transmembrane glycoprotein MUC1 and cytoplasmic miRNA-21 and trigger gene silencing therapy.