【摘要】 目的利用核酸适配体(aptamer)建立一种检测与疾病有关蛋白质的新方法。方法用金纳米颗粒(AuNP)修饰的寡核苷酸适配子与蛋白质结合,同时另一个生物素化的寡核苷酸适配子也结合于蛋白质,构成一个三明治形式的复合物,接着三明治复合物被卵白素结合于酶标板上,利用银离子强化技术对复合物上的蛋白质浓度信息进行放大,然后用酶标仪对吸光度进行检测。结果(1)本研究可以得到吸光度与PDGF-BB浓度的剂量-效应关系曲线,在一定的浓度范围内(1fM~1μM),吸光度与PDGF-BB浓度的对数值呈线形相关,决定系数R2=0.9801;(2)本方法可以检测出1fmol/L的靶蛋白质。结论本方法有较高灵敏度,不需要复杂的仪器,易于操作,是一种新颖而应用前景的蛋白质标志物分析方法。更多还原

【Abstract】 Objective An ultrasensitive colorimetric method for detecting protein by nanoparticle-modified aptamer was established. Methods In this assay, target protein was bound to nanoparticle-modified aptamer and another aptamer probe modified with biotion together forming a sandwich-like complex.Thereafter, the sandwich-like complex was captured in microwell by avidin.After amplification by silver-enhancement, the absorbance resulted from aptamer-protein complex was determined by colorimetry. Results In the range of 1 fM-1 μM, the absorbance induced by the concentration of PDGF was dose-dependent, R~2=0.9801. The minimal detection limit was 1fM of targeted protein.Conclusion this new NP-modified aptamer assay could offer an ultrasensitive detection for protein. It requires no complicated or expensive instrument and is easy to use. It has a good future for detecting ultratrace level of disease-related protein markers that can not be detected by conventional methods.更多还原