SPR生物传感器快速检测大肠杆菌O157:H7的研究

建立了一种基于表面等离子体共振(surface plasmon resonance,SPR)原理的生物传感器方法,实现了快速检测大肠杆菌O157:H7.研究选用BIACORE 3000系统及葡聚糖修饰的CM5芯片,先用EDC/NHS将芯片活化,然后抗体直接通过酰胺键固定在金表面,再用乙醇胺封闭,这样处理之后的芯片就可用于检测大肠杆菌O157:H7.利用NaOH溶液对芯片再生,实现对多个不同浓度样品检测,采用时间对响应单位(RU)记录数据.该法检测大肠杆菌O157:H7的检测限为3×105 CFU·mL-1,RU变化值和大肠杆菌O157:H7的浓度在一定范围内相关性良好,相关系数达到0.99.检测时间短,一个样品仅需5～7 min,再生效果好,芯片可重复使用50次以上.可快速、在线、稳定地检测大肠杆菌O157:H7,有望成为一种在线检测食品致病性微生物的有力手段.

Rapid detection of Escherichia coli O157 : H7 using surface plasmon resonance (SPR) biosensor

A biosensor based on surface plasmon resonance (SPR) was developed for rapid detection of Escherichia coli O157 : H7. BIACORE 3000 SPR instrument and a dextran-modified sensor chip (CM5) were used. After activation with EDC/NHS, anti-E. coli O157 : H7 antibody was immobilized on the gold surface of the SPR sensor, and then following ethanolamine was injected, and the chip was ready for E. coli O157 : H7. Regeneration was achieved using NaOH in order to detect several samples. The limit of detection was found to be 3 x 10(5) CFU x mL(-1) for E. coli O157 : H7, and the change of RU was linearly correlated with the concentration of E. coli O157 : H7 cells (R2 = 0.99). The detection time ranged from 5 to 7 min, and the result of regeneration was effective which allowed the chip to be reused for more than 50 samples. This method is convenient, and stable, and shows potentials for applications in food areas.