Intracellular label-free gold nanorods imaging with photoacoustic microscopy

Noninvasive photoacoustic microscopy was developed to image intracellular gold nanorods with high optical-absorption contrast. The endocytosed gold nanorods in MCF7 cells can be detected and imaged with the home-made photoacoustic microscope. Cell nucleus and gold nanorods in cytoplasm were clearly identified after hematoxylin and eosin (H&E) staining with dual-wavelength excitation. The intracellular gold nanorods were successfully monitored, and that the time-dependent uptake and distribution of the gold nanorods in the cells were clearly shown. The result demonstrated an application of photoacoustic microscopy for complements to imaging of nonfluorescent nanoparticles, which will arm the in vivo microscopic imaging method to the nano-bio research.