Photodynamic control of harmful algal blooms by an ultra-efficient and degradable AIEgen-based photosensitizer

Harmful algal blooms (HABs) have a severe impact on human health, aquatic ecosystems, and the economy. There is still a lack of effective means to control algal blooms. Herein, TVP-A, a positively charged photosensitizer with aggregation-induced emission (AIE) characteristics is introduced as a super-efficient, cost-effective, and eco-friendly agent for the governance of HABs. TVP-A efficiently harvests white light to generate reactive oxygen species (ROS). Due to its positive surface charge, TVP-A has good water solubility and quickly adsorbs onto algal cells floating on the surface of water, triggering algal cell death through oxidative destruction of the nuclei and chloroplasts of algae. TVP-A is effective at low concentrations and requires sunlight irradiation periods of only a few minutes to destroy algal blooms, making it applicable for large scale algal bloom control under most weather conditions. Further, TVP-A is non-toxic to fish, mice or mammalian cells. The slow self-degradation of TVP-A during the photodynamic control of algal blooms prevents environmental accumulation or secondary pollution to ecological systems. TVP-A therefore serves as an excellent candidate for the green governance of HABs.