DNA-Conjugated Gold Nanoparticles as High-Mass Probesin Imaging Mass Cytometry

We employ Imaging Mass Cytometry™ (IMC™) to investigate in vitro uptake and cellular distribution of DNA-functionalized gold nanoparticles (AuNP). IMC enables the multiparametric imaging of cell components and allows for the detection of AuNP in cells with >100 times higher sensitivity than conventional confocal fluorescence imaging, as each nanoparticle contains thousands of atoms for signal amplification. Changes in the accumulation of nanoparticles in cells due to oligonucleotide sequence-dependent interactions are exploited to examine a model biomarker for hypoxia – microRNA-210. We find that AuNP functionalized with microRNA-210-targeting sequence accumulate in hypoxic cells 3 to 4-fold compared to normoxic cells. The work examines the potential use of DNA-AuNP as high-mass probes for the analysis of non-abundant nucleic acids.