Chen Desheng, Zhang Xiaobo, Zhu Liping, Liu Chenghui, Li Zhengping
Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University Xi'an 710119 Shaanxi Province P. R. China
Beijing Key Laboratory for Bioengineering and Sensing Technology, School of Chemistry and Biological Engineering, University of Science and Technology Beijing 30 Xueyuan Road, Haidian District Beijing 100083 P. R. China
Chem Sci. 2022 Feb 17;13(12):3501-3506. doi: 10.1039/d1sc07048g. eCollection 2022 Mar 24.
Ultrasensitive protein analysis is of great significance for early diagnosis and biological studies. The core challenge is that many critical protein markers at extremely low aM to fM levels are difficult to accurately quantify because the target-induced weak signal may be easily masked by the surrounding background. Hence, we propose herein an ultrasensitive immunoassay based on a modular Single Bead Enrich-Amplify-Amplify (SBEAA) strategy. The highly efficient enrichment of targets on only a single bead (enrich) could confine the target-responsive signal output within a limited tiny space. Furthermore, a cascade tyramide signal amplification design enables remarkable signal enhancement just affixed to the target. As a result, the efficient but space-confined fluorescence deposition on a single bead will significantly exceed the background and provide a wide dynamic range. Importantly, the SBEAA system can be modularly combined to meet different levels of clinical need regarding the detection sensitivity from aM to nM. Finally, a size-coded SBEAA set (SC-SBEAA) is also designed that allows ultrasensitive multi-immunoassay for rare samples in a single tube.
超灵敏蛋白质分析对于早期诊断和生物学研究具有重要意义。核心挑战在于，许多极低至阿托摩尔（aM）到飞摩尔（fM）水平的关键蛋白质标志物难以准确量化，因为目标诱导的微弱信号可能很容易被周围背景所掩盖。因此，我们在此提出一种基于模块化单珠富集-放大-放大（SBEAA）策略的超灵敏免疫测定法。仅在单个珠子上对目标进行高效富集（富集）可以将目标响应信号输出限制在有限的微小空间内。此外，级联酪胺信号放大设计能够在仅附着于目标时实现显著的信号增强。结果，在单个珠子上高效但空间受限的荧光沉积将大大超过背景，并提供宽动态范围。重要的是，SBEAA系统可以模块化组合，以满足从aM到nM不同水平的临床检测灵敏度需求。最后，还设计了一种尺寸编码的SBEAA集（SC-SBEAA），可在单个试管中对稀有样本进行超灵敏多免疫测定。
