Biogenic
amines (BAs) are known as substantial indicators of the
quality and safety of food. Developing rapid and visual detection
methods capable of simultaneously monitoring BAs is highly desired
due to their harmful effects on human health. In the present study,
we have designed a multicolor sensor array consisting of two types
of gold nanostructures (i.e., gold nanorods (AuNRs) and gold nanospheres
(AuNSs)) for the discrimination and determination of critical BAs
(i.e., spermine (SM), tryptamine (TT), ethylenediamine (EA), tyramine
(TR), spermidine (SD), and histamine (HT)). The design principle of
the probe was based on the metallization of silver ions on the surface
of AuNRs and AuNSs in the presence of BAs, forming Au@Ag core–shell
nanoparticles. Changes in the surface composition, size, and aspect
ratio of AuNSs and AuNRs induced a blue shift in the plasmonic band,
which was accompanied by sharp and rainbowlike color variations in
the solution. The collected data were visually assessed and statistically
analyzed by various data visualization and pattern recognition methods.
Namely, linear discriminant analysis (LDA) and partial least squares
(PLS) regression were employed for the qualitative and quantitative
determination of BAs. The responses were linearly correlated to the
concentrations of BAs in a wide range of 10–800, 20–800,
40–800, 40–800, 60–800, and 80–800 μmol
L–1 with the limit of detections of 2.46, 4.79,
8.58, 14.26, 10.03, and 27.29 μmol L–1 for
SD, SM, TT, HT, EA, and TR, respectively. Finally, the practical applicability
of the sensor array was investigated by the determination of BAs in
meat and fish samples by which the potential of the probe for on-site
determination of food freshness/spoilage was successfully verified.