Abstract：
Development of a simple and efficient dual-mode analytical technique with the built-in cross reference correction feature is benefit to achieve the highly accurate detection of the target pollutants and avoid the false-positive outputs in environmental media. Here, we synthesized a Fe-doped polydopamine (Fe@PDA)-based nanozyme with prominent peroxide-mimetic enzyme activity and high fluorescence emission ability. On this basis, we designed a dual-recognition strategy-driven fluorescence-colorimetric dual-mode detection platform, consisting of Listeria monocytogenes (L. monocytogenes) recognition aptamer-modified Fe@PDA (apt/Fe@PDA) and vancomycin-functionalized Fe3O4 (van/Fe3O4), for L. monocytogenes. Owing to van/Fe3O4-powered magnetic separation, there was a L. monocytogenes concentration-dependent fluorescence enhancement of apt/Fe@PDA for performing fluorescence assay in the precipitate. In this case, the prominent peroxide-mimetic enzyme activity of the residual apt/Fe@PDA in the precipitation could catalyze H2O2 to further oxidate colorless 3,3\',5,5\'-tetramethylbenzidine (TMB) into blue oxTMB, which displayed a L. monocytogenes concentration-dependent absorbance enhancement for carrying out colorimetric assay as well. As a result, a fluorescence-colorimetric dual-mode analytical platform was proposed to successfully detect the residual L. monocytogenes in real environmental media with acceptable results. This work showed the great prospects by integrating dual-recognition strategy into fluorescence nanozyme to develop efficient and reliable dual-mode analytical platforms for safeguarding environmental health.
摘要：
开发具有内置交叉参考校正功能的简单高效的双模式分析技术有利于实现对目标污染物的高精度检测，并避免环境介质中的假阳性输出。这里,我们合成了一种基于Fe掺杂的聚多巴胺（Fe@PDA）的纳米酶，具有突出的过氧化物模拟酶活性和高荧光发射能力。在此基础上,设计了双识别策略驱动的荧光比色双模检测平台,由单核细胞增生李斯特菌(L.单核细胞增生）识别适体修饰的Fe@PDA（apt/Fe@PDA）和万古霉素功能化的Fe3O4（van/Fe3O4），单核细胞增生李斯特菌。由于van/Fe3O4动力磁分离，对于在沉淀物中进行荧光测定,存在apt/Fe@PDA的单核细胞增生李斯特菌浓度依赖性荧光增强。在这种情况下,沉淀中残留的apt/Fe@PDA突出的过氧化物模拟酶活性可以催化H2O2进一步氧化无色3,3\'，5,5'-四甲基联苯胺（TMB）变成蓝色oxTMB，这也显示了用于进行比色测定的单核细胞增生李斯特菌浓度依赖性吸光度增强。因此,我们提出了一个荧光比色双模分析平台,成功地检测了真实环境介质中残留的单核细胞增生李斯特菌,结果可接受.通过将双识别策略集成到荧光纳米酶中，以开发有效可靠的双模式分析平台来维护环境健康，这项工作显示了巨大的前景。
