Au@Ag Core–Shell
Nanoparticles for Colorimetric
and Surface-Enhanced Raman-Scattering-Based Multiplex Competitive
Lateral Flow Immunoassay for the Simultaneous Detection of Histamine
and Parvalbumin in Fish
Foodborne allergies and illnesses represent a major global
health
concern. In particular, fish can trigger life-threatening food allergic
reactions and poisoning effects, mainly caused by the ingestion of
parvalbumin toxin. Additionally, preformed histamine in less-than-fresh
fish serves as a toxicological alert. Consequently, the analytical
assessment of parvalbumin and histamine levels in fish becomes a critical
public health safety measure. The multiplex detection of both analytes
has emerged as an important issue. The analytical detection of parvalbumin
and histamine requires different assays; while the determination of
parvalbumin is commonly carried out by enzyme-linked immunosorbent
assay, histamine is analyzed by high-performance liquid chromatography.
In this study, we present an approach for multiplexing detection and
quantification of trace amounts of parvalbumin and histamine in canned
fish. This is achieved through a colorimetric and surface-enhanced
Raman-scattering-based competitive lateral flow assay (SERS-LFIA)
employing plasmonic nanoparticles. Two distinct SERS nanotags tailored
for histamine or β-parvalbumin detection were synthesized. Initially,
spherical 50 nm Au@Ag core–shell nanoparticles (Au@Ag NPs)
were encoded with either rhodamine B isothiocyanate (RBITC) or malachite
green isothiocyanate (MGITC). Subsequently, these nanoparticles were
bioconjugated with anti-β-parvalbumin and antihistamine, forming
the basis for our detection and quantification methodology. Additionally,
our approach demonstrates the use of SERS-LFIA for the sensitive and
multiplexed detection of parvalbumin and histamine on a single test
line, paving the way for on-site detection employing portable Raman
instruments.