基于氧化单壁碳纳米角的荧光适配体传感器对胰岛素的检测

A simple fluorescent aptasensor for the detection of insulin based on oxidized single-walled carbon nanohorns

构建了一种基于氧化单壁碳纳米角(oxSWCNHs)荧光适配体传感器用于胰岛素的检测。合成了水溶性的单壁碳纳米角和羧基荧光素(FAM)标记的胰岛素适配体,该适配体能与胰岛素进行高亲和力和强特异性的结合。当体系中没有胰岛素存在时,FAM标记的适配体可以被oxSWCNHs吸附,致使体系具有较低的荧光强度;当体系中有胰岛素存在时,胰岛素可以与其适配体进行强特异性结合,导致FAM标记的适配体远离oxSWCNHs表面,FAM荧光不能被oxSWCNHs淬灭,体系具有较强的荧光强度,实现荧光强度的增强。研究了淬灭剂的用量、反应时间的影响,同时进行了选择性、干扰实验和实际样品分析等。该传感器的线性范围为0~1.6 nmol/L,检出限为0.1 nmol/L,可用于小鼠血清中胰岛素的测定。

A simple fluorescent aptasensor for the detection of insulin by assembling a dye-labeled aptamer with oxidized single-walled carbon nanohorns(oxSWCNHs)was described.To construct the sensor for insulin,watersoluble oxSWCNHs and carboxyfluorescein(FAM)labeled aptamer were synthesized,which could bind insulin with high affinity and specificity.Addition of oxSWCNHs into the solution of a FAM-labeled aptamer led to the formation of the oxSWCNHs-aptamer complex.In the presence of insulin,however,the FAM-labeled aptamer would form a structure by the self-assembly of two components as a consequence of the specific substrate recognition,causing the release of the FAM-labeled aptamer from oxSWCNHs and thereby the fluorescence recovery.The effects of the amount of oxSWCNHs,the reaction time,the selectivity,the interference experiment and the analysis of real samples had been studied.The linear range of the aptasensor was 0-1.6 nmol/L and the limit of detection was 0.1 nmol/L.Furthermore,the aptasensor can be used for the determination of insulin in mouse serum.