纳米钯电化学适配体传感器用于血管内皮生长因子的检测

Nano-palladium modified electrochemical aptasensor for vascular endothelial growth factor detection based on split aptamers

基于目标诱导适配体片段连接,以修饰于电极表面的纳米Pd作为适配体固定平台,构建检测血管内皮生长因子(VEGF)的电化学适配体传感器。方法将VEGF适配体切成两段,其一为捕获探针,通过Pd-S键固定在以电沉积和二硫苏糖醇(DTT)封闭相结合法制备的纳米钯修饰电极表面;其二为信号探针,3’端修饰有二茂铁基团。由于VEGF与适配体之间强的相互作用,可连接此两段适配体序列并在电极表面形成稳定的适配体复合物,此时二茂铁靠近电极表面,产生电信号,从而实现对VEGF的检测。结果表明,在pH 7.0的Tris-HCl缓冲溶液中,二茂铁的峰电流与VEGF浓度在5~40 pmol/L范围呈良好线性关系,检测限为0.4 pmol/L。

Based on the target-induced conjunction of split aptamer fragments and nano palladium modified electrode,a sensitive and specific electrochemical aptasensor for the determination of vascular endothelial growth factor(VEGF)was developed.The VEGF aptamer was split in two parts,one acted as capture probe and the other as signal probe.The capture probe was immobilized on the surface of nano-palladium modified electrode via the Pd-S bond,and the signal probe was modified with ferrocene groups at the 3’-terminal.In the presence of VEGF,the two split aptamer would be connected to form a stable complex at the electrode surface due to the strong binding between aptamer and VEGF,resulting that ferrocene groups got close to the electrode surface and thus the occurrence of the electrical signal.The results showed that there was a good linear relationship between peak current of ferrocene and VEGF concentration in the range of 5-40 pmol/L with the detection limit of 0.4 pmol/L.