Performance analysis of QDs-LFIAS detection
The main advantage of a lateral flow immunoassay system is
the integration of sample pre-treatment, separation, reaction and
detection in one strip. However, quantifying the resultant signal is
usually difficult, which restricts the utility of these assays. In this
study, samples were mixed with QDs–Ab, and both H9 (or H5)
subtype viruses in the sample and QDs–Ab moved forward to the
absorbent pad when added to the sample pad of the strip and
were captured by the immobilized capture antibodies in the test
line to form a sandwich structure (Fig. 1); the fluorescence signals
of QDs were measured by a handheld device (Fig. 1). Compared
with the broad application of gold nanoparticle-based lateral flow
immunoassay, our approach quantified the fluorescence intensity
of bound QDs on test line (Fig. 1) and consequently was able to measure the related virus concentration.