纳米金增强SPR检测产毒赭曲霉中PKS基因的特异性碱基

基于双通道表面等离子体子共振(surface plasmon resonance,SPR)传感器,分别采用直接法和金纳米粒子作为传感层的方法,通过检测赭曲霉毒素A(ochratoxin A,OTA)合成初期阶段表达的聚酮合成酶(polyketide synthase,PKS)基因的25个特异性碱基的寡核苷酸链,建立了一种高灵敏、间接检测OTA的新方法.同时考察了6-巯基己醇(6-mercapto-1-hexanol,MCH)作为封闭液对SPR响应信号的影响.结果表明,直接法的检测限为12.5 nmol/L,MCH的加入可使响应信号有所增强,使用金纳米粒子作为传感层的检测下限为0.25 nmol/L,与直接法相比较灵敏度提高了50倍,与以往使用金纳米粒子标记抗体或抗原相比,其作为传感层也能大大提高SPR检测灵敏度,且操作简单易行.

Detection for Polyketide Synthase Gene of Aspergillus ochraceus Based on Au Nanoparticles Enhancing SPR Biosensor

The surface plasmon resonance(SPR) method is established for indirect detection of the ochra-toxin A.The 25-base oligonucleotide sequence of polyketide synthase(PKS) gene which is expressed during early stage of ochratoxin A synthesis,was detected respectively using direct assay and Au nanoparticles as sensing membrane assay based on the two channels surface plasmon resonance(SPR) biosensor.At the same time,influence of 6-mercapto-1-hexanol(MCH) blocking on SPR signal was also studied.As a result,the limit of detection(LOD) of the direct assay was 12.5 nmol/L.And the SPR signal was enhanced with 6-mercapto-1-hexanol(MCH) blocking.With Au nanoparticles as a sensing membrane,LOD was 0.25 nmol/L,sensitivity was 50 times higher than that of direct detection.SPR signal could be dramatically en-hanced with Au nanoparticles as sensing membrane instead of as label,and the operation was simple.