How Exactly Do AIEgens Target Bacteria? Leveraging the Targeting Mechanism to Design Sensitive Fluorescent Immunosensors

作者：Leina Dou, Qing Li, Yuchen Bai, Jiaqian Kou, Xiaonan Wang, Qian Zhao, Xuezhi Yu, Kai Wen, Zhanhui Wang, Jianzhong Shen, Wenbo Yu · 发表于：Analytical Chemistry · 年份：2023 · DOI：10.1021/acs.analchem.2c04983 · 被引用次数：32 · 研究领域：Luminescence and Fluorescent Materials、Advanced biosensing and bioanalysis techniques、Nanoplatforms for cancer theranostics

Aggregation-induced emission luminogens (AIEgens) are promising candidates for bacterial imaging and detection because they can “Light-Up” pathogenic bacteria without complicated labeling or washing steps. However, there have been few in-depth analyses of the intrinsic mechanism underlying their utility as fluorescence probes for targeting bacteria. Therefore, using large-scale molecular dynamics simulations, we investigated the mechanism of their bacterial “Light-Up” behavior with N, N -diphenyl-4-(7-(pyridin-4-yl)benzo[c][1,2,5]thiadiazol-4-yl) aniline functionalized with 1-bromoethane (TBP-1). We propose that the triphenylamine motif of TBP-1, rather than the positively charged pyridine group, first contacts the cell membrane. After TBP-1 completely inserts into the cell membrane, the hydrophobic triphenylamine motif localizes in the hydrophobic core of the cell membrane, restricting the molecular variation of TBP-1, which induces the fluorescent “turn-on” and bacterial “Light-Up.” On this basis, we established a heterogeneous lateral flow immunoassay (LFIA) for the detection of foodborne pathogens. The LFIA system showed improved sensitivity with a limit of detection as low as 10 3 CFU mL –1 and strong specificity. Our protocol opened an effective shortcut to the design of more efficient AIEgens and novel AIEgens-based immunoassays.