Cancer theranostics that integrate cancer detection with cancer treatment provide a practical strategy for cancer diagnosis and therapy. Based on the therapeutic potential of miRNAs, we are developing a series of multi-functional probes that can form hydrogels to encapsulate miRNAs or form nanocomplex with miRNAs for miRNA delivery, therapy and function imaging (Chem. Eur. J. 2018, 24, 2277; Org. Biomol. Chem. 2017, 15, 2191; Chem. Commun. 2016, 52, 12517; Chem. Commun. 2014, 50, 3722).