Development of a Competitive Indirect Enzyme-Linked Immunosorbent Assay Based on Monoclonal Antibodies for the Detection of 2?Dodecylcyclobutanone in Irradiated Beef

摘要

A highly sensitive and specific competitive indirect enzyme-linked immunosorbent assay (ciELISA) based on monoclonal antibodies was developed for the detection of 2~dodecylcycIobutanone (2-DCB), a chemical marker for irradiated lipid-containing foods. 2-Oxocyclobutane undecanoic acid was used as an alternative to 2-DCB and conjugated to BSA and OVA via a conventional carbodiimide condensation reaction to prepare the immunogen and the coating antigen for 2-DCB. The monoclonal antibody against 2-DCB was obtained using the hybridoma technique, with a high specificity and low cross-reactivity for 2-tetradecylcyclobutanone (2-TCB; <8%) and other structurally related compounds (<0.1%). The ciELISA method was applicable at optimal experimental conditions of 0.001—100 μg/mL 2-DCB in a buffer solution, with an IC_(50) value of 0.25 μg/mL and a limit of detection (defined as the IC_(20)) of approximately 0.004 μg/mL. The recovery efficiency of 2-DCB from ground beef patties ranged from 84.4 to 109.8%. The intra-assay and interassay coefficients of variation were <10.0 and <12.0%, respectively. The proposed method was validated by gas chromatography—mass spectrometry with high correlation. The same method was used to detect 2-DCB in ground beef patties irradiated at 0.5, 1.0, 3.0, 5.0, and 7.0 kGy; the 2-DCB concentration linearly increased with the radiation dose.