A fluorescent immunochromatographic strip test using Quantum Dots for fumonisins detection

•A QD-based strip test for fumonisin B1 qualitative and quantitative detection.•Reagents synthesis, preparation, optimization and performing of assay is described.•Direct comparison of QD, gold nanoparticles and chemiluminescent as ICST labels.•The test allowed ultrasensitive fumonisins detection in maize flour samples.

A fluorescent immunochromatographic strip test (ICST) based on the use of Quantum Dots (QD) was developed and applied to detect fumonisins in maize samples. A limit of detection for fumonisin B1 of 2.8 µg L−1 was achieved, with an analytical working range of 3–350 µg L−1, corresponding to 30–3500 µg kg−1 in maize flour samples, according with the extraction procedure. The time required to perform the analysis was 22 min, including sample preparation. Recovery values in the range from 91.4% to 105.4% with coefficients of variation not exceeding 5% were obtained for fortified and naturally contaminated maize flour samples. To evaluate the possible improvements due to the use of QD for ICST technology, we performed a direct comparison of the proposed QD-ICST to a gold nanoparticles- and a chemiluminescent-ICST previously developed for fumonisins detection, in which the same immunoreagents were employed.

Graphical abstractThe fluorescent immunochromatographic strip test based on the use of Quantum Dots as labels for the sensitive and rapid detection of fumonisins (FMs) in maize flour. The test allows the rapid and simple visual detection of FM contaminations and the quantitative determination of FMs at levels of regulatory interest.Figure optionsDownload full-size imageDownload as PowerPoint slide