Figure 1.

Schema of Au-based probes measured by nanoSIMS. Secondary antibodies were conjugated to Au_Np (ball) with a size of 6 nm, 15 nm and 1.4 nm, and the 1.4 nm-conjugated antibody was additionally conjugated to a fluorophore (star). The nanobody (Nb) was conjugated to 3 nm Au_Np. All of them enable the affinity labeling of target molecules. The 5 nm Au_Np can be attached to His-tagged proteins through the binding of its conjugated nickel-NTA to His-tags.