Typhimurium poses a serious threat to human health worldwide, necessitating the development of a rapid, sensitive, and convenient method for . Typhimurium detection. Nanozymes are considered ideal signal report elements, which are extensively used for developing colorimetric methods. However, single-component nanozymes display low catalytic activity, and colorimetric methods are susceptible to environmental interference, reducing the sensitivity and accuracy of detection results. To address these drawbacks, this study constructed a dual-mode composite nanozyme-based cascade colorimetric-fluorescence aptasensor for . Typhimurium detection in food. In this study, the composite FeO@MIL-100(Fe) nanozymes were successful synthesized and demonstrated substantial peroxide-like activity, with 4.76-fold higher specificity activity (SA) than that of FeO nanozymes. Then, a glucose oxidase (GOx)-FeO@MIL-100(Fe) cascade reaction was developed for colorimetric detection via an aptamer to facilitate the formation of FeO@MIL-100(Fe)/. Typhimurium/carboxylated g-CN (CCN)-GOx sandwich complexes. Meanwhile, the fluorescence mode was achieved by measuring the fluorescence intensity of the sandwich complexes. In optimum conditions, the dual-mode detection limits (LOD) were 1.8 CFU/mL (colorimetric mode) and 1.2 CFU/mL (fluorescence mode), respectively, with the . Typhimurium concentration ranging from 10 CFU/mL to 10 CFU/mL. Finally, the feasibility of the dual-mode colorimetric-fluorescence method was validated via three actual samples, yielding recovery rates of 77.32 % to91.17 % and 82.17 % to 103.7 %, respectively. This study successfully develops a composite nanozyme-based cascade colorimetric and fluorescence dual-mode aptasensor for . Typhimurium detection. It presents several distinct benefits, such as a broader linear range (10–10 CFU/mL), a lower LOD value (1.2 CFU/mL), and more accurate results. More importantly, the proposed dual-mode method displays a low LOD in colorimetric mode, demonstrating considerable potential for . Typhimurium on-site detection in food.

中文翻译：

---

用于鼠伤寒沙门氏菌检测的双模式复合纳米酶级联比色荧光适体传感器


鼠伤寒对全世界人类健康构成严重威胁，因此需要开发一种快速、灵敏且方便的方法来检测鼠伤寒。鼠伤寒杆菌检测。纳米酶被认为是理想的信号报告元件，广泛用于开发比色方法。然而，单组分纳米酶催化活性较低，比色法易受环境干扰，降低了检测结果的灵敏度和准确性。为了解决这些缺点，本研究构建了一种基于双模式复合纳米酶的级联比色荧光适体传感器。食品中鼠伤寒菌的检测。本研究成功合成了复合Fe3O@MIL-100(Fe)纳米酶，并表现出类似过氧化物的活性，其特异性活性(SA)是Fe3O纳米酶的4.76倍。然后，开发了葡萄糖氧化酶（GOx）-FeO@MIL-100（Fe）级联反应，通过适体进行比色检测，以促进FeO@MIL-100（Fe）/的形成。鼠伤寒/羧化 g-CN (CCN)-GOx 夹心复合物。同时，通过测量夹心配合物的荧光强度来实现荧光模式。在最佳条件下，双模式检测限 (LOD) 分别为 1.8 CFU/mL（比色模式）和 1.2 CFU/mL（荧光模式）。鼠伤寒菌浓度范围为 10 CFU/mL 至 10 CFU/mL。最后通过三个实际样品验证了双模式比色荧光法的可行性，回收率分别为77.32%~91.17%和82.17%~103.7%。本研究成功开发了一种基于复合纳米酶的级联比色和荧光双模式适体传感器。鼠伤寒杆菌检测。 它具有多种明显的优点，例如更宽的线性范围 (10–10 CFU/mL)、更低的 LOD 值 (1.2 CFU/mL) 和更准确的结果。更重要的是，所提出的双模式方法在比色模式下显示出低 LOD，展示了巨大的潜力。食品中鼠伤寒杆菌现场检测。