为检测食品中的重金属镉残留问题，本研究建立了基于重金属镉抗体的酶联免疫分析方法。利用异硫氰酸苄基乙二胺四乙酸（Isothiocyanobenzyl-EDTA，ITCBE）螯合Cd2+并偶联牛血清白蛋白（BSA）和卵清白蛋白（OVA），合成了针对Cd2+的免疫原Cd-ITCBE-BSA和包被原Cd-ITCBE-OVA，通过紫外扫描鉴定说明偶联成功；以Cd-ITCBE-BSA免疫Balb/c小鼠，制备出Cd2+抗血清并对其免疫学特性进行鉴定，进一步说明了抗原合成成功，在此基础上进行了条件优化并建立了针对镉的icELISA检测方法。方法的检测限（IC10）为0.18 ng/mL，IC50为1.15 ng/mL，线性检测范围（IC20~IC80）为0.24~5.54 ng/mL。除了与Hg2+有2.16%的交叉反应率，该方法对Pb2+、Fe3+、Cu2+和Cr3+交叉反应率均小于0.3%，板内变异系数和板间变异系数都低于10%。此抗体特异性强灵敏度高，建立的icELISA方法可应用于食品中重金属镉的快速检测。

An enzyme-linked immunosorbent assay (ELISA) for the determination of heavy metal Cadmium ion (Cd2+) residues in food was established. ITCBE was coupled with Cd2+ and conjugated to bovine serum albumin (BSA) and ovalbumin (OVA) to obtain Cd-ITCBE-BSA as immunogen and Cd-ITCBE-OVA as coating antigen, which were identified by ultraviolet spectrum (UV). Cd-ITCBE-BSA was injected to Balb/c mice to produce antiserum. The immunological characteristics of the antiserum were identified, which further proved the success of synthesis. On this basis, an ic-ELISA was established after optimizing the conditions. The limit of detection (IC10) was 0.18 ng/mL, the 50% inhibitory concentration (IC50) was 1.15 ng/mL, and the linear range (IC20~IC80) was 0.24~5.54 ng/mL. Except for a cross-reactivity of 2.16% with Hg2+, the cross-reactivity with Pb2+, Fe3+, Cu2+ and Cr3+ were all less than 0.3%. The coefficients of variation within and between plates were both less than 10%. This antibody has strong specificity and high sensitivity, and the established ELISA method can be applied to the rapid detection of heavy metal cadmium in food.

国家重点研发计划项目（2018YFC1602903）；广东省科技计划项目（2014B070706001）