摘要

Two novel surface plasmon resonance immunosensors were fabricated for detection of the Bacillus thuringiensis Cry1Ab protein and to demonstrate their performance in analyzing Cry1Ab protein in crop samples. Sensor 2 was modified by 1,6-hexanedithiol, Au/Ag alloy nanoparticles, 3-mercaptopropionic acid, and protein A (or not [sensor 1]), with Cry1Ab monoclonal antibody. As a result, both of the immunosensors exhibited satisfactory linear responses in the Cry1Ab protein concentration ranges of 10 to 500 ng ml(-1) and 8 to 1000 ng ml(-1), and the detection limits were 5.0 and 4.8 ng ml(-1), respectively. The immunosensors possessed good specificity and acceptable reproducibility. In addition, crop samples could be analyzed after a simple treatment. The transgenic crops could be easily identified from the conventional ones by the two immunosensors.