Preparation of high stable core/shell magnetic nanoparticles and application in Bacillus thuringiensis Cry1Ac proteins detection

The silicon coated Magnetic nanoparticles (MNps) were prepared and applied to the genetically modified detection for Cry1Ac protein. TEM observations showed the bare MNps were in the size of 3–5   nm and the silicon coated core/shell MNps were in the range of 30–60   nm 1   M HCl acidic solution was used to test the chemical stability of the resultant MNps and results showed the coated MNps were very stable in the acid environment even after 12   h. Cy3 labelled IgG tests showed that the probe on the MNps was kept the bioactivity in the immunoassays. MNps based detection results showed that this analytical strategy had similar linear relation which R   =   0.995 with the commercial ELISA kit. The MNps based detections were reliable for the Cry1 Ac protein in the linear range from 0.1   pg/L to 1.0   mg/L, and showed better performance in the low concentration of analyte. This study provides a promising technique to detect the Cry1Ac protein with high sensitivity in the examination of the GM products which is of importance in food safety.