A Bifunctional Aggregation-Induced Emission Luminogen for Monitoring and Killing of Multidrug-Resistant Bacteria

Multidrug-resistant (MDR) bacteria pose serious threats to public health as there is currently a lack of effective and biocompatible drugs to kill MDR bacteria. Here, a bifunctional aggregation-induced emission luminogen (AIEgen), triphenylethylene-naphthalimide triazole (TriPE-NT), is reported, which is capable of both staining and killing Gram-positive (G+) and Gram-negative (G−) bacteria. The intrinsic fluorescence generating ability of the TriPE unit enables TriPE-NT to monitor the drug–bacteria interactions, meanwhile, the NT unit renders TriPE-NT the antibacterial activity. Furthermore, TriPE-NT can generate reactive oxygen species (ROS) under light irradiation and drastically enhance its antibacterial efficacy by photodynamic therapy against wild bacteria and clinical isolated MDR bacteria with a very low toxicity to mammalian cells. Moreover, the efficiency of TriPE-NT staining on bacteria closely correlates with its antibacterial efficacy. As an example of application, TriPE-NT is utilized in curing Escherichia coli- (E. coli), MDR E. coli-, Staphylococcus epidermidis- (S. epidermidis), and MDR S. epidermidis- infected wounds on rats with high efficacy and high safety. Thus, TriPE-NT can be used not only as a powerful antibiotic agent for treating MDR bacteria-infected diseases but also as a potential fluorescent agent for monitoring the bacterial infections and further exploring the related antibacterial mechanism.