基于CMK-3(Au/Fc@MgAl-LDH)n纳米复合材料修饰的电化学传感器检测miRNA-21

Detection of miRNA-21 with electrochemical sensor modified based on CMK-3(Au/Fc@MgAl-LDH)n nanocomposites

目的基于CMK-3(Au/Fc@MgAl-LDH)n纳米复合材料修饰的电化学传感器建立一种灵敏、快速、稳定的方法用于检测miRNA-21。方法本文建立了基于有序介孔碳(CMK-3)、金纳米粒子(AuNPs)和包含二茂铁甲酸的镁铝双层氢氧化物(Fc@MgAl-LDH)纳米材料修饰的电化学传感器用于检测卵巢癌标志物miRNA-21。成功合成了CMK-3(Au/Fc@MgAl-LDH)n纳米复合材料,并对其表面形貌、元素组成和表面基团进行了表征。通过差分脉冲伏安法(DPV)对传感器进行响应信号测定,对纳米材料组装层数、底液pH值、孵育时间和温度进行了优化。结果得到最佳实验条件为:层数4层、pH=6.5、孵育时间40 min、孵育温度35℃。在最优实验条件下,检测miRNA-21的标准曲线为△I=9.939 logC+147.89,r^(2)=0.9971,在10^(-14)mol/L~10^(-9)mol/L线性范围内具有良好的响应,检出限(LOD)为0.48×10^(-14)mol/L(S/N=3)。对血清样品进行加标回收测定,回收率为94.6%~100.0%。结论该方法灵敏、准确、特异性强,可用于血清中miRNA-21的测定。

Objective This study aims to establish a sensitive,rapid and stable method for the detection of miRNA-21 with electrochemical sensor which is modified based on CMK-3(Au/Fc@MgAl-LDH)nnanocomposites.Methods An electrochemical sensor based on ordered mesoporous carbon(CMK-3),gold nanoparticles(AuNPs)and magnesium aluminum double hydroxides containing ferrocenoformic acid(Fc@MgAl-LDH)was developed for the detection of ovarian cancer marker,miRNA-21.CMK-3(Au/Fc@MgAl-LDH)nnanocomposites were successfully synthesized,and their surface morphology,elemental composition and surface groups were characterized.The response signal of the sensor was measured by differential pulse voltammetry(DPV),and the number of assembly layers,pH of the substrate,incubation time and temperature of the nanomaterials were optimized.Results The optimal experimental conditions were as follows:4 layers,pH=6.5,incubation time of 40 min,incubation temperature of 35℃.Under the optimal experimental conditions,the standard curve of miRNA-21 detection is△I=9.939 logC+147.89,with r^(2)=0.9971,which has a good response within the linear range of 10^(-14)mol/L to 10^(-9)mol/L.The detection limit(LOD)was 0.48×10^(-14)mol/L(S/N=3).The recoveries of serum samples were within 94.6%-100.0%.Conclusion The method is sensitive,accurate and specific,and can be used for the determination of miRNA-21 in serum.