Liu Mengyue, Xu Shicai, Marrazza Giovanna
Shandong Provincial Key Laboratory of Biophysics, Institute of Biophysics, Dezhou University, Dezhou, 253023, Shandong, China.
"Ugo Schiff" Chemistry Department, University of Florence, Via Della Lastruccia 3, 50019, Sesto Fiorentino, FI, Italy.
Mikrochim Acta. 2025 Apr 1;192(4):272. doi: 10.1007/s00604-025-07138-5.
Multivalent engineering aptamers (multi-Apts) adaptive and specific to whole Escherichia coli (E. coli: CMCC 44102) cells based on hybridization chain reaction (HCR) were constructed for the first time. The dissociation constant (K) value for these multi-Apts was 48 nM, demonstrating a higher affinity than that of monovalent aptamers (mono-Apts) (K = 102 nM). Furthermore, the reaction equilibrium of multi-Apts was achieved within 20 min, with a reaction rate twice that of mono-Apts. To validate the exceptional performance of these multi-Apts, they were employed as recognition elements in conjunction with gold nanoparticles (AuNPs) colorimetric assays for the all-in-one rapid detection of E. coli. This method exhibited a linear detection range from 1 × 10 to 1 × 10⁷ CFU mL⁻, achieving a limit of detection (LOD) as low as 19 CFU mL⁻. The recovery of this method in tap water and milk were 85.7% to 101% and 81.8% to 98.2%, respectively. The results indicated that this method not only provided a wide detection range but also exhibited high sensitivity and accuracy. Additionally, this study demonstrated that multi-Apts possessed greater application potential in the detection of macromolecular substances such as bacteria. In short, this work provided a novel approach for rapid and all-in-one detection of E. coli in food.
首次构建了基于杂交链式反应（HCR）的、对全细胞大肠杆菌（大肠杆菌：CMCC 44102）具有适应性和特异性的多价工程适配体（多适配体）。这些多适配体的解离常数（K）值为48 nM，表明其亲和力高于单价适配体（单适配体）（K = 102 nM）。此外，多适配体的反应平衡在20分钟内即可达到，反应速率是单适配体的两倍。为了验证这些多适配体的卓越性能，将它们作为识别元件与金纳米颗粒（AuNPs）比色测定法结合，用于大肠杆菌的一体化快速检测。该方法的线性检测范围为1×10至1×10⁷ CFU mL⁻，检测限（LOD）低至19 CFU mL⁻。该方法在自来水和牛奶中的回收率分别为85.7%至101%和81.8%至98.2%。结果表明，该方法不仅提供了宽检测范围，而且具有高灵敏度和准确性。此外，本研究表明多适配体在检测细菌等大分子物质方面具有更大的应用潜力。简而言之，这项工作为食品中大肠杆菌的快速一体化检测提供了一种新方法。
