Zhang Ling, Zhang Kaixiang, Liu Guangchao, Liu Mengjia, Liu Yang, Li Jinghong
Department of Chemistry, Beijing Key Laboratory for Analytical Methods and Instrumentation, Tsinghua University, Beijing 100084, China.
Anal Chem. 2015 Jun 2;87(11):5677-82. doi: 10.1021/acs.analchem.5b00791. Epub 2015 May 15.
Rapid and sensitive detection of biomarkers with ultralow concentrations remains a great challenge in disease diagnostics. Herein, we present a label-free α-hemolysin (α-HL) nanopore proximity bioassay for protein biomarker detection by a binding-induced DNA strand displacement strategy. In this bioassay, an individual target protein, platelet-derived growth factor B-chain (PDGF-BB), was selectively recognized by two oligonucleotide affinity ligands in which an output DNA was released and translocated through α-HL nanopore with a spikelike short current block. The frequency of the current block events had a linear relationship with the concentration of PDGF-BB with a wide linear dynamic range of 5 orders of magnitude and a detection limit at 500 fM. The selectivity and anti-interference capability of this bioassay show great potential for biomarker detection in bioanalytical chemistry.
对超低浓度生物标志物进行快速灵敏的检测在疾病诊断中仍然是一项巨大挑战。在此，我们提出一种无标记的α-溶血素（α-HL）纳米孔邻近生物测定法，用于通过结合诱导的DNA链置换策略检测蛋白质生物标志物。在这种生物测定法中，单个目标蛋白血小板衍生生长因子B链（PDGF-BB）被两个寡核苷酸亲和配体选择性识别，其中一个输出DNA被释放并通过α-HL纳米孔进行易位，产生一个尖峰状的短电流阻断。电流阻断事件的频率与PDGF-BB的浓度呈线性关系，线性动态范围宽达5个数量级，检测限为500 fM。这种生物测定法的选择性和抗干扰能力在生物分析化学中的生物标志物检测方面显示出巨大潜力。
