Light-Enhanced Bacterial Killing and Wash-Free Imaging Based on AIE Fluorogen

Abstract

The rapid acquisition of antibiotic resistance poses difficulties in the development of effective methods to eliminate pathogenic bacteria. New bactericides, especially those do not induce the emergence of resistance, are thus in great demand. In this work, we report an aggregation-induced emission fluorogen, TPE-Bac, for bacterial imaging and elimination. TPE-Bac can be readily dissolved in aqueous solution with weak emission. The presence of bacteria can turn on its emission, and thus no washing step is required in the imaging process. Meanwhile, TPE-Bac can be applied as a bactericide for elimination of bacteria. The amphiphilic TPE-Bac bearing two long alkyl chains and two positively charged amines can intercalate into the membrane of bacteria, increase membrane permeability and lead to dark toxicity. The efficiency of bacteria killing is greatly enhanced under light irradiation. TPE-Bac can serve as a photosensitizer to induce reactive oxygen species (ROS) generation, which ensures the efficient killing of bacteria. The TPE-Bac-containing agar plates can be continuously used for bacteria killing by applying light to induce ROS generation.

Membrane‐Anchoring Photosensitizer with Aggregation‐Induced Emission Characteristics for Combating Multidrug‐Resistant Bacteria

“…Motivated by the initial success, we and others have further developed AIE probes to detect and kill bacteria . These probes generally light‐up in response to bacteria, so that the detection can be done in real time without washing steps . Some of these probes also showed obvious dark toxicity, which can be combined with light‐induced photosensitization to effectively kill bacteria even under sunlight .…”

A Luminogen with Aggregation‐Induced Emission Characteristics for Wash‐Free Bacterial Imaging, High‐Throughput Antibiotics Screening and Bacterial Susceptibility Evaluation

“…Through systematic studies, restriction of intramolecular motion (RIM) was identified as the main cause for the AIE effect . These AIE luminogens (AIEgens) show great potential in biological research, and lots of biological applications have been developed with these materials, including cell and bacteria imaging, tissue and tumor visualization, therapy, and drug delivery . The fluorescence turn‐on characteristics of the AIEgens upon binding to the targets make them excellent candidates as fluorescence sensors and inspire us to explore their potentials in bacterial susceptibility evaluation and antibiotics screening.…”

“…A new AIEgen 4 was synthesized following the procedures reported previously (Scheme S2, Supporting Information) . The cross McMurry coupling reaction of 4‐hydroxybenzophenone and 4‐bromobenzophenone gave 1 , which then underwent Williamson ether synthesis reaction by treatment of 1‐bromoundecane to form 2 .…”

Selective Cu2+ Ion Sensing by Nanoaggregates of Pyridyl‐2,6‐bis(3‐allylsalicylaldehyde)hydrazone

“…The correlation between the aggregation process and morphologies of aggregates in different solvents is of elemental importance . “AIEgens” for imaging of bacteria and photodynamic killing have been reported by Tang et al . They have also been used for the generation of metal nanoparticles ,.…”