State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha, 410082, China.
Mikrochim Acta. 2020 Mar 30;187(4):251. doi: 10.1007/s00604-020-4183-1.
A novel surface plasmon resonance (SPR) strategy is introduced for the specific determination of exosomes based on aptamer recognition and polydopamine-functionalized gold nanoparticle (Au@PDA NP)-assisted signal amplification. Exosomes derived from hepatic carcinoma SMMC-7721 were selected as the model target. SMMC-7721 exosomes can be specifically captured by the aptamer ZY-sls that was complementary to the DNA tetrahedron probes (DTPs), and then the CD63 aptamer-linked Au@PDA NPs recognized SMMC-7721 exosomes for signal amplification. The DTPs were modified on a Au film for preventing Au deposition on the surface during the introduction of HAuCl, and PDA coated on the AuNPs was used to reduce HAuCl in situ without any reductant assistance. It results in a further enhanced SPR signal. The assay can clearly distinguish SMMC-7721 exosomes from others (HepG2 exosomes, Bel-7404 exosomes, L02 exosomes, MCF-7 exosomes, and SW480 exosomes, respectively). SMMC-7721 exosomes are specifically determined as low as 5.6 × 10 particles mL. The method has successfully achieved specific determination of SMMC-7721 exosomes even in 50% of human serum without any pretreatment. Graphical abstract A novel surface plasmon resonance (SPR) strategy was introduced for the specific determination of exosomes based on aptamer recognition and polydopamine functionalized gold nanoparticles (Au@PDA NPs). The SPR signal was improved using the Au@PDA NPs assisted amplification.
一种新颖的表面等离子体共振（SPR）策略，基于适体识别和聚多巴胺功能化金纳米粒子（Au@PDA NPs）辅助信号放大，用于外泌体的特异性测定。选择肝癌 SMMC-7721 衍生的外泌体作为模型靶标。SMMC-7721 外泌体可以被与 DNA 四面体探针（DTPs）互补的适体 ZY-sls 特异性捕获，然后 CD63 适体连接的 Au@PDA NPs 识别 SMMC-7721 外泌体进行信号放大。DTPs 修饰在 Au 膜上，以防止在引入 HAuCl 时 Au 在表面沉积，并且 PDA 包覆在 AuNPs 上，在没有任何还原剂辅助的情况下原位还原 HAuCl，从而导致进一步增强的 SPR 信号。该测定法可以清楚地区分 SMMC-7721 外泌体与其他外泌体（HepG2 外泌体、Bel-7404 外泌体、L02 外泌体、MCF-7 外泌体和 SW480 外泌体）。SMMC-7721 外泌体的特异性检测低至 5.6×10 个颗粒/mL。该方法甚至在未经任何预处理的情况下，在 50%的人血清中也成功地实现了 SMMC-7721 外泌体的特异性测定。
