Development of a chemiluminescent enzyme immunoassay to detect cadmium in cereal samples

• Main Authors: Zhi-Li Xiao, Wei Tian, Zhen-Lin Xu, Yuan-Ming Sun
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2018-01-01
• Series: Food and Agricultural Immunology
• Subjects: cadmium; chemiluminescence immunoassay; cereals; analysis
• Online Access: http://dx.doi.org/10.1080/09540105.2018.1527295

In this study, we develop a sensitive indirect competitive chemiluminescent enzyme immunoassay (ic-CLEIA) to detect cadmium (Cd) in cereals. A luminol-hydrogen peroxide chemiluminescence system catalysed by horseradish peroxidase (HRP) was used as the signal detecting system. The method showed a half-maximal inhibition concentration (IC50) of 0.5 ng/mL and a limit of determination (LOD) of 0.06 ng/mL. The assay indicated an effective linear range from 0.16 to 1.56 ng/mL. There were no obvious cross-reactivities with other metal ions, including Hg2+, Pb2+, As2+, Ag+, Fe3+, Cu2+, Cr2+, Au3+, Ca2+, Mg2+, Mn2+ and Zn2+. Recovery rates ranged from 79.2% to 120.0% for rice, maize, wheat, brown rice and glutinous rice samples. Twenty-five practical cereal samples were analysed, and the comparative analysis of the results showed a strong correlation (r = 0.984) between the CLEIA and the GFAAS methods. The results indicated that the ic-CLEIA developed was acceptable to screen for cadmium in cereal samples.