ELISA and chemiluminescent enzyme immunoassay for sensitive and specific determination of lead (II) in water, food and feed samples

Lead is a heavy metal with increasing public health concerns on its accumulation in the food chain and environment. Immunoassays for the quantitative measurement of environmental heavy metals offer numerous advantages over other traditional methods. ELISA and chemiluminescent enzyme immunoassay (CLEIA), based on the mAb we generated, were developed for the detection of lead (II). In total, 50% inhibitory concentrations (IC50) of lead (II) were 9.4 ng/mL (ELISA) and 1.4 ng/mL (CLEIA); the limits of detection (LOD) were 0.7 ng/mL (ic-ELISA) and 0.1 ng/mL (ic-CLEIA), respectively. Cross-reactivities of the mAb toward other metal ions were less than 0.943%, indicating that the obtained mAb has high sensitivity and specificity. The recovery rates were 82.1%–108.3% (ic-ELISA) and 80.1%–98.8% (ic-CLEIA), respectively. The developed methods are feasible for the determination of trace lead (II) in various samples with high sensitivity, specificity, fastness, simplicity and accuracy.This research was funded by National Natural Science Foundation of China, grant numbers 31572556, 31873006; the Key Program for International S&T Cooperation Project of Shaanxi Province, grant number 2017KW-ZD-10; and the Incubation Project on State Key Laboratory of Biological Resources and Ecological Environment of Qinba Areas, grant number SLGPT2019KF04-04