Surface-enhanced Raman spectroscopy (SERS) has been successfully applied to detect various biomolecules, but it is still in challenge to assay living cells or bacteria sensitively, selectively and quantitatively in complex environments. In this paper, 4-ATP and DTNB are assembled on Ag nanoparticle (NP) -decorated poly (styrene-co-acrylic acid) (PSA) nanospheres and then sealed by silica shells to form sensitive SERS labels based on the localized surface plasmon resonance of Ag NPs and large light scattering cross-sections of PSA nanospheres. They are further developed as encoding tags for dual detection of S. aureus and E. coli after assembling corresponding aptamers, which demonstrate ultralow detection limits of 8 cell L⁻¹ for S. aureus and 2 cell L^-1 for E. coli. Such a bioassay indicates a point-of-care strategy of ultrasensitively biomedical detections by encoding specific SERS tags.

表面增强拉曼光谱（SERS）已成功地用于检测各种生物分子，但在复杂环境中灵敏，选择性和定量地分析活细胞或细菌仍然面临挑战。本文将4-ATP和DTNB组装在装饰有Ag纳米颗粒（NP）的聚（苯乙烯-丙烯酸）（PSA）纳米球上，然后用二氧化硅壳密封，以基于局部表面等离子体激元共振形成敏感的SERS标签。 Ag NPs和PSA纳米球的大光散射截面。它们被进一步开发作为编码的双重检测标签的金黄色葡萄球菌和大肠杆菌组装相应的适体，其表现出的8单元L超低检测限之后^-1为金黄色葡萄球菌和2细胞L ^-1的大肠杆菌。这种生物测定法通过编码特定的SERS标签指示了超灵敏生物医学检测的即时战略。