School of Food & Biological Engineering, Hefei University of Technology, Hefei, 230009, China.
Department of Food Science and Technology, Jinan University, Guangzhou, China.
Mikrochim Acta. 2024 Jul 1;191(7):438. doi: 10.1007/s00604-024-06460-8.
A dual-recognition strategy is reported to construct a one-step washing and highly efficient signal-transduction tag system for high-sensitivity colorimetric detection of Staphylococcus aureus (S. aureus). The porous (gold core)@(platinum shell) nanozymes (Au@PtNEs) as the signal labels show highly efficient peroxidase mimetic activity and are robust. For the sake of simplicity the detection involved the use of a vancomycin-immobilized magnetic bead (MB) and aptamer-functionalized Au@PtNEs for dual-recognition detection in the presence of S. aureus. In addition, we designed a magnetic plate to fit the 96-well microplate to ensure consistent magnetic properties of each well, which can quickly remove unreacted Au@PtNEs and sample matrix while avoiding tedious washing steps. Subsequently, Au@PtNEs catalyze hydrogen peroxide (H2O2) to oxidize 3,3',5,5'-tetramethylbenzidine (TMB) generating a color signal. Finally, the developed Au@PtNEs-based dual-recognition washing-free colorimetric assay displayed a response in the range of S. aureus of 5 × 10-5 × 10 CFU/mL, and the detection limit was 40 CFU/mL within 1.5 h. In addition, S. aureus-fortified samples were analyzed to further evaluate the performance of the proposed method, which yielded average recoveries ranging from 93.66 to 112.44% and coefficients of variation (CVs) within the range 2.72-9.01%. These results furnish a novel horizon for the exploitation of a different mode of recognition and inexpensive enzyme-free assay platforms as an alternative to traditional enzyme-based immunoassays for the detection of other Gram-positive pathogenic bacteria.
报道了一种双重识别策略，用于构建一步式洗涤和高效信号转导标签系统，用于高灵敏度比色检测金黄色葡萄球菌（S. aureus）。多孔（金核）@（铂壳）纳米酶（Au@PtNEs）作为信号标签具有高效过氧化物酶模拟活性且坚固。为了简单起见，检测涉及使用万古霉素固定化磁珠（MB）和适配体功能化的 Au@PtNEs 进行双重识别检测，在存在金黄色葡萄球菌的情况下。此外，我们设计了一个磁板来适应 96 孔微孔板，以确保每个孔的磁性能一致，这可以快速去除未反应的 Au@PtNEs 和样品基质，同时避免繁琐的洗涤步骤。随后，Au@PtNEs 催化过氧化氢（H2O2）氧化 3,3',5,5'-四甲基联苯胺（TMB）生成颜色信号。最后，开发的基于 Au@PtNEs 的双重识别免洗比色测定法在金黄色葡萄球菌的范围内显示出 5×10-5×10 CFU/mL 的响应，并且在 1.5 小时内检测限为 40 CFU/mL。此外，还分析了添加了金黄色葡萄球菌的样品，以进一步评估所提出方法的性能，该方法的平均回收率范围为 93.66%至 112.44%，变异系数（CV）在 2.72%至 9.01%范围内。这些结果为利用不同的识别模式和廉价的无酶测定平台提供了新的前景，作为传统基于酶的免疫测定法的替代方法，用于检测其他革兰氏阳性致病菌。
Zotero 插件