Fig. 1.

BoNT/A LC activated complex assay (BACA) for bacterial or virus diagnosis. The target nucleic acid was amplified through universal polymerase chain reaction (PCR). Sequence-specific amplicons were then captured by streptavidin magnetic beads (MB) followed by recruitment of BoNT/A LC and anti-TAG sequence dually modified BNPs, forming magnetic nanocomplexes. Fluorescent signals generated upon the SNAPtide cleavage activity of BoNT/A LC on the magnetic nanocomplexes. Moreover, the color changes of the assay could be observed with naked eyes or UV–vis spectra. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)