[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.