A cationic AIE luminutesogen TBPD²⁺-6C as a potential bacterial detection agent and bactericide for plants bacterium

The rise of plant bacterial pathogens poses a significant threat to the yield and quality of essential food crops and cash crops globally. Our research introduced a versatile cationic AIE fluorescent probe for detecting and eliminating plant bacteria. With its unique aggregation-induced emission property, TBPD²⁺-6C can effectively detect plant bacteria by causing a fluorescence quenching effect and enables bacterial imaging under green fluorescence channels. Additionally, TBPD²⁺-6C demonstrates outstanding antibacterial effectiveness, with EC₅₀ values of 0.27, 3.86, 0.47, and 11.5 μg/mL against Xanthomonas oryzae pv. oryzicola (Xoc), X. oryzae pv. oryzae (Xoo), Pseudomonas syringae pv. actinidiae (Psa), and X. axonopodis pv. citri (Xac), respectively. In vivo testing against Xoc revealed that TBPD²⁺-6C showed better activity than commercial thiodiazole copper (TC) and bismerthiazol (BT). Furthermore, the investigation into the antibacterial mechanism revealed that the cationic compound can effectively integrate into the bacterial membrane, disrupt the membrane structure, trigger ROS accumulation, and inhibit biofilm formation. In conclusion, the development of multifunctional, broad-spectrum antimicrobial system molecular designs for rapid real-time detection, imaging, and elimination of resistant microbes could play a vital role in combating pathogens.