摘要： Dark-?eld microscopy (DFM) based on localized surface plasmon resonance (LSPR) was used for observation of experimental phenomena, which is a hopeful nondamaging and non-photobleaching biological imaging technique. In this strategy, plasma nanoaggregates with stronger scattering e?ciency were formed in the presence of the target, causing a “turn-on” phenomenon, when asymmetry modi?ed AuNPs were introduced as probes with zero LSPR background. First, ?CC probe were designed for the cycloaddition between azide and alkyne Au1 to form AuNP dimers under catalytic action by Cu+, which was obtained from the reduction of Cu2+ by sodium ascorbate. The two kinds of probes were successfully used for the detection of Cu2+ in rat serum. Then, to apply this concept to protein on cells, DNA and antibody were modi?ed on the ?CC probe were proposed for HER2 protein DFM on cells. By designing an aptamer sequence in primer, the rolling circle ampli?cation (RCA) was introduced in HER2 DFM on cells, and the image signal was much brighter than that from no-RCA. The unique design made it easier to discriminate the target signal from background noise in cell DFM. This method might be used in the ?elds of molecular diagnostics and cell imaging.