Diketopyrrolopyrrole‐derived organic small molecular dyes for tumor phototheranostics

Cancer is one of the leading causes of human death around the world. Phototherapy, including photodynamic therapy (PDT) and photothermal therapy (PTT), is an emerging light-triggered cancer treatment and shows the advantages of non-invasiveness and low side effects. The design and preparation of efficient phototherapeutic agents are of great significance for phototherapy. Diketopyrrolopyrrole (DPP) is a small molecular organic dye featuring outstanding photophysical properties, facile tuning of structures and properties, and excellent photostability; thus, phototherapeutic agents based on organic small molecular DPP derivatives have attracted significant research attention for not only phototherapy but also photodiagnosis of fluorescence imaging (FLI) and photoacoustic imaging (PAI). This review summarizes the recent progress of various DPP-based organic small molecules on phototheranostics during the last five years. The molecular structure design and their phototheranostics performances are discussed in detail, as will be of great help for further creation of DPP-based phototheranostics.