1.Department of Chemistry,University of Turin,Turin,Italy
Abstract:
The authors describe the preparation of desert rose-like gold nanoparticles (DR-GNPs) with a plasmon resonance band at 620 nm which gives them a blue color. They have a hydrodynamic diameter of ～72 nm and were prepared by a seeding growth approach. The DR-GNPs were characterized by UV-vis spectroscopy, transmission electron microscopy and dynamic light scattering. These nonspherical GNPs were used as a label for the antibody in an immunochromatographic strip test (ICST). Despite their particular shape and the higher surface area compared to spherical gold nanoparticles, the DR-GNPs are useful blue labels for the GNP-based strip test. A multicolor ICST for aflatoxin B1 and fumonisins is described that employs both blue DR-GNPs and red spherical GNPs. It allows for simultaneous rapid determination of the two mycotoxins in maize flour, with visual cut-off levels of 2 μg?kg-1 for aflatoxin B1 and of 1000 μg?kg-1 for fumonisins.
Graphical abstract Blue desert rose-like gold nanoparticles (DR-GNPs) were synthesized, characterized and applied as label for the ImmunoChromatographic Strip Test (ICST) technique, in which red spherical GNPs (s-GNPs) are usually employed. The combined use of the blue DR-GNP and red s-GNPs allowed developing of an intuitive multicolor ICST for the simultaneous detection of aflatoxin B1 and fumonisins in maize flour.
