Complexity made easy: Aggregation‐induced emission small molecules for cancer diagnosis and phototherapies

Abstract Phototheranostics has garnered sustained attention due to its significant potential for revolutionizing conventional cancer treatment strategies. While being one of the most commonly employed strategies for constructing phototheranostic systems by engineering the integration of photosensitizers (PSs) into nanosystems, nano‐PSs face challenges including complexity in the preparation process, low delivery efficiency, and potential toxicity issues. Contrastingly, the burgeoning popularity of small molecule PSs characterized by aggregation‐induced emission (AIE) has become evident in the arena of cancer phototheranostics. This preference is underscored by their well‐defined structures, adjustable photophysical properties, and low toxicity. Therefore, acquiring profound insights into the pioneering strides achievable through a solitary small molecule PS with AIE in tumor phototheranostics is of paramount scientific significance. In this review, we will discuss the recent progress of small molecule PSs with AIE properties in cancer diagnosis and phototherapies with representative examples, guided by the ethos of “Complexity made easy”. We also look forward to the future development direction of AIE small molecules, with a central objective of advancing cancer research through a focal emphasis on simplicity, expeditiousness, and safety.