Double-codified nanogold particles based automated flow-through CLEIA for 2,4-dinitrotoluene

Abstract

A sensitive, automated micro flow-through chemiluminescence enzyme immunoassay (CLEIA) was developed for the determination of 2,4-dinitrotoluene (DNT) which employed a DNT analog covalently immobilized on a glass microchip, and nanogold particles (AuNPs) modified with HRP-labeled anti-mouse antibodies. The HRP-luminol-H₂O₂ chemiluminescent system (because of its high sensitivity) was chosen as the detection system. The obtained chemiluminescence (CL) intensity was inversely proportional to the DNT concentration in the sample. The working range for DNT quantification was 0.01–1 μg mL⁻¹. Both the intra- and inter-assay coefficients of variation were less than 10%. The proposed assay had a LOD of 0.009 μg mL⁻¹, which was 3-fold lower than a traditional HRP-labeled anti-mouse antibody-based CLEIA. The overall assay time was 13 min for each sample, enabling relatively rapid analysis.