The concept of AIE was first coined by Prof. Tang in 2001, describing a photophysical phenomenon in which molecular aggregates exhibit stronger emission than the single molecules . So far, the working mechanism of AIE has been well investigated, which is summarized as restriction of intramolecular motion (RIM), including restriction of intramolecular rotations (RIR) and restriction of intramolecular vibration (RIV) (Fig. ) . The propeller-shaped (tetraphenylethene, TPE) or butterfly-shaped (cyclooctatetrathiophene) molecules display almost no emission in dilute solutions or single molecular state, while show intensive emission in aggregate state . In comparison with inorganic luminescent materials and traditional ACQ luminogens, AIEgens hold many advantages, including easy-tunable chemical structure, large Stokes shift, high sensitivity in biological microenvironments, superior photostability, good biocompatibility, excellent long-term tracking capability, and so on . Thus, the fluorescent materials with AIE characteristics are excellent candidates for biological imaging and diagnostic applications . Apart from the superior luminescent performance in aggregate state, AIE materials also exhibit promising photodynamic and photothermal activity through regulating the intersystem crossing efficiency and excited state molecular motion in aggregate state. The excellent photodynamic and photothermal properties of AIEgens enable their promising applications for theranostics of pathogenic infections . The detailed working mechanism of AIE photosensitizers and photothermal agents could be principally understood by the classical Jablonski diagram as shown in Fig. . After excitation from the ground state (S0) to higher excited states (S n ), the exciton will decay to the lowest singlet excited state (S 1 ) according to Kasha's rule, . In general, there are three decay pathways for the excitons. For example, returning to S 0 state and emitting fluorescence by a radiative pathway, which potentially could be used for fluorescence sensing and imaging . Additionally, the S 1 can also be deactivated through nonradiative decay pathway accompanied by generating heat, which provides an pathway to develop organic photothermal agent for photothermal therapy (PTT) . Besides, the excitons at S 1 can also relax to the lowest triplet state (T 1 ) through the intersystem crossing (ISC) to sensitize 3 O 2 to generate reactive oxygen species (ROS) for photodynamic therapy (PDT) . Since ACQ effect will quench the singlet excited state, the ROS efficiency of ACQ photosensitizers (PSs) thus are strongly suppressed in the aggregate state . As a contrast, the ROS efficiency of AIE PSs don't suffer the ACQ effect but exhibit an enhancement upon aggregation due to the suppression of non-radiative decay .