Label-free photoacoustic nanoscopy

Amos Danielli, Konstantin Maslov, Alejandro Garcia-Uribe, Amy M. Winkler, Chiye Li, Lidai Wang, Yun Chen, Gerald W. Dorn, Lihong V. Wang

Research output: Contribution to journalArticlepeer-review

121 Scopus citations


Super-resolution microscopy techniques-capable of overcoming the diffraction limit of light-have opened new opportunities to explore subcellular structures and dynamics not resolvable in conventional far-field microscopy. However, relying on staining with exogenous fluorescent markers, these techniques can sometimes introduce undesired artifacts to the image, mainly due to large tagging agent sizes and insufficient or variable labeling densities. By contrast, the use of endogenous pigments allows imaging of the intrinsic structures of biological samples with unaltered molecular constituents. Here, we report label-free photoacoustic (PA) nanoscopy, which is exquisitely sensitive to optical absorption, with an 88 nm resolution. At each scanning position, multiple PA signals are successively excited with increasing laser pulse energy. Because of optical saturation or nonlinear thermal expansion, the PA amplitude depends on the nonlinear incident optical fluence. The high-order dependence, quantified by polynomial fitting, provides super-resolution imaging with optical sectioning. PA nanoscopy iscapable of super-resolution imaging of either fluorescent or nonfluorescent molecules.

Original languageEnglish
Article number086006
JournalJournal of Biomedical Optics
Issue number8
StatePublished - Aug 2014
Externally publishedYes


  • label-free
  • microscopy
  • mitochondria
  • nanoscopy
  • photoacoustics
  • super-resolution


Dive into the research topics of 'Label-free photoacoustic nanoscopy'. Together they form a unique fingerprint.

Cite this