By virtue of the fascinating merits of low cost, rapid
screening,
and on-site detection, fluorescence lateral flow assays (FLFAs) have
attracted considerable attention. Their detection limits are closely
associated with the label probes used. The development of high-performance
and robust phosphors remains a great challenge. Herein, we presented
a new label probe, i.e., fluorescent carbon nanobeads (FCNBs), for
FLFAs. Monodispersive, water-soluble, and highly emissive FCNBs were
facilely prepared via a hydrothermal carbonization manner. Their abundant
amino groups were beneficial for versatile surface functionalization.
After being modified by biomolecules, the fabricated FCNB reporter
probes were adopted for the construction of lateral flow test strips
toward representative foodborne toxins, i.e., aflatoxin B1 (AFB1),
and pathogenic bacteria, i.e., Staphylococcus aureus (S. aureus), respectively. The detection
limits (0.01 ng/mL for AFB1 and 102 cfu/mL for S. aureus) were about 1 or 2 orders of magnitude
lower than most reported methods. Furthermore, the proposed test strips
were successfully applied for the quantitative, accurate, and rapid
screening of AFB1 and S. aureus in
food samples. This work provided a promising label probe for FLFAs
and would open the opportunity to exploit a sensing platform by modifying
different ligands onto the FCNBs.