College of Food Science and Engineering, Northwest A&F University, Yangling 712100, Shaanxi, China.
College of Food Science and Technology, Henan Agricultural University, Zhengzhou 450002, Henan, China.
Anal Chem. 2023 Jun 20;95(24):9237-9243. doi: 10.1021/acs.analchem.3c00743. Epub 2023 May 26.
Nanozymes have drawn much attention as an enzyme mimetic with low cost and stability in enhancing analytical performance. Herein, a peroxidase-mimicking nanozyme-improved enzyme-linked immunosorbent assay (ELISA) was developed employing the bimetallic PdRu nanozyme to replace the natural enzymes as a catalytic carrier for the sensing of O157:H7 ( O157:H7). The PdRu nanozyme displayed ultrahigh catalytic activity, possessing a catalytic rate that was 5-fold higher than horseradish peroxidase (HRP). In addition, PdRu exhibited great biological affinity with antibody (affinity constant was about 6.75 × 10 M) and high stability. All those advantages ensure the successful establishment and the construction of a novel colorimetric biosensor for O157:H7 detection. PdRu-based ELISA not only achieved an ultrasensitive detection sensitivity (8.7 × 10 CFU/mL) by approximately 288-fold as compared to the traditional HRP-based ELISA and also possessed satisfactory specificity and reproducibility (relative standard deviation (RSD) < 10%). Furthermore, the feasibility of PdRu-ELISA was further evaluated by detecting O157:H7 in actual samples with satisfactory recoveries, indicating its potential for applications in bioassays and clinical diagnostics.
纳米酶作为一种具有低成本和稳定性的酶模拟物，在提高分析性能方面引起了广泛关注。本文采用双金属 PdRu 纳米酶作为催化载体，取代天然酶，构建了一种过氧化物酶模拟物增强的酶联免疫吸附测定法（ELISA），用于检测 O157:H7（O157:H7）。PdRu 纳米酶具有超高的催化活性，其催化速率是辣根过氧化物酶（HRP）的 5 倍。此外，PdRu 与抗体具有很强的生物亲和力（亲和力常数约为 6.75×10^M），且稳定性高。所有这些优势确保了新型比色生物传感器用于 O157:H7 检测的成功建立和构建。基于 PdRu 的 ELISA 不仅比传统的基于 HRP 的 ELISA 具有高 288 倍的超灵敏检测灵敏度（8.7×10^CFU/mL），而且还具有令人满意的特异性和重现性（相对标准偏差（RSD）<10%）。此外，通过用实际样品检测 O157:H7，进一步评估了 PdRu-ELISA 的可行性，回收率令人满意，表明其在生物测定和临床诊断中的应用潜力。
