Immunochromatographic assay for melamine based on luminescent quantum dot beads as signaling probes

• Published in: RSC advances Vol. 1; no. 6; pp. 337 - 3313
• Main Authors: Chen, Quan, Qie, Meifang, Peng, Xusheng, Chen, Yan, Wang, Yulin
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 20.01.2020; The Royal Society of Chemistry
• Subjects: Assaying; Beads; Chemistry; Melamine; Milk; Nanoparticles; Optimization; Pretreatment; Product safety; Quantum dots
• DOI: 10.1039/c9ra08350b
• ISSN: 2046-2069

To screen and detect the harmful substance melamine (MEL), a quantum-dot-bead-based immunochromatographic assay (QB-ICA) was formulated. After optimization, calibration was performed within the linear range from 0.06 to 0.28 ng mL −1 , with limit of detection (LOD) of 0.04 ng mL −1 . The LOD was 35 times lower than that of ICA that used colloidal gold nanoparticles (LOD = 1.4 ng mL −1 ) and 40 times lower than that of the assay based on quantum dots (LOD = 1.6 ng mL −1 ). In the detection of MEL in spiked pure milk using the proposed QB-ICA strategy, the LOD (LOD = 0.19 ng mL −1 ) of the samples with the proposed pretreatment was 18.4 times lower than those of the samples without pretreatment (LOD = 3.5 ng mL −1 ). The performance and practicability of the proposed QB-ICA system was validated; the obtained results reveal that QB-ICA is comparable with the conventional enzyme-linked immunosorbent assay (ELISA) method, but with enhanced applicability. Given its high sensitivity and practicability, the QB-ICA strategy could become a worthwhile alternative for the rapid, sensitive, and quantitative onsite detection of harmful substances, facilitating food safety monitoring. An immunochromatographic assay using quantum dot beads as a label was established for melamine detection in milk with fast and effective pretreatment.