National Key Laboratory of Veterinary Public Health Security, College of Veterinary Medicine China Agricultural University, Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, and Beijing Laboratory for Food Quality and Safety, Beijing 100193, People's Republic of China.
Anal Chem. 2023 Mar 28;95(12):5223-5231. doi: 10.1021/acs.analchem.2c04983. Epub 2023 Mar 15.
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 ,-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 CFU mL and strong specificity. Our protocol opened an effective shortcut to the design of more efficient AIEgens and novel AIEgens-based immunoassays.
聚集诱导发光团（AIEgens）是用于细菌成像和检测的有前途的候选物，因为它们可以在不需要复杂标记或洗涤步骤的情况下“点亮”致病菌。然而，对于它们作为荧光探针用于靶向细菌的内在机制，还很少有深入的分析。因此，我们使用大规模的分子动力学模拟，研究了用 1-溴乙烷（TBP-1）功能化的 4-（7-（吡啶-4-基）苯并[c][1,2,5]噻二唑-4-基）-二苯基-4-（7-（吡啶-4-基）苯并[c][1,2,5]噻二唑-4-基）苯胺（TBP-1）作为荧光探针用于靶向细菌的“点亮”行为的机制。我们提出，TBP-1 的三苯胺基序，而不是带正电荷的吡啶基团，首先与细胞膜接触。TBP-1 完全插入细胞膜后，疏水性三苯胺基序定位在细胞膜的疏水区，限制了 TBP-1 的分子变化，从而诱导荧光“开启”和细菌“点亮”。在此基础上，我们建立了一种用于检测食源性病原体的异质横向流动免疫分析（LFIA）。LFIA 系统显示出改进的灵敏度，检测限低至 10 CFU mL，并且具有很强的特异性。我们的方案为设计更有效的 AIEgens 和基于 AIEgens 的新型免疫分析方法开辟了一条有效的捷径。
