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  • Review Article
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Transition metal complexes as optical probes for super-resolution microscopy

Nature Reviews Chemistry volume 9, pages 733–748 (2025)Cite this article

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Abstract

The suite of techniques encompassing optical super-resolution microscopy can facilitate detailed visualization of biological structures and biochemical transformations at unprecedented levels of resolution and contrast; however, they depend on imaging probes with specific biophysical and photophysical properties. In this context, metal complexes with tuneable photo-excited states and stability towards photobleaching are promising candidates for advanced imaging techniques. This Review illustrates how, by selecting appropriate optical properties and luminescence responses, metal complexes can be utilized as probes for a range of super-resolution microscopy techniques, including multimodal imaging, to study subcellular architecture and dynamics with nanoscale resolution. Limitations and challenges of the existing molecular probes are also discussed. By highlighting these recent innovations and providing suggestions for future directions, this Review further underscores the importance of optical probes in pushing the boundaries of super-resolution microscopy and advancing our understanding of complex biological systems.

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Fig. 1: CLSM and STED nanoscopy using RuII-based organelle-targeting probes.
Fig. 2: Multiple imaging modalities of RuII complex 3.
Fig. 3: SRM imaging of bacteria using antimicrobial theragnostic complexes 4 and 5.
Fig. 4: Live MCF-7 cell uptake of Ru/Re complex 7; comparison of d-CLSM images and d-STED microscopic images.
Fig. 5: Examples of the use of OsII and IrIII complexes as super-resolutions live cell probes in both prokaryotes and eukaryotes.
Fig. 6: CLEM can be combined with SRM when using selected metal complexes.
Fig. 7: Imaging cellular processes and sub-organelle structures with late-transition or post-transition metal complexes.
Fig. 8: MnII complexes as multimodal super-resolution microscopy probes.

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Authors and Affiliations

  1. CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar, India

    Sumit Kumar Pramanik

  2. College of Science and Engineering, University of Derby, Derby, UK

    Sreejesh Sreedharan

  3. Indian Institute of Science Education and Research Kolkata, Mohanpur, India

    Noufal Kandoth & Amitava Das

  4. National Heart and Lung Institute, Imperial College London, London, UK

    Jorge Bernardino de la Serna

  5. Central Laser Facility, Science and Technology Facilities Council, United Kingdom Research and Innovation, Didcot, UK

    Jorge Bernardino de la Serna

  6. Department of Chemistry, University of Sheffield, Sheffield, UK

    Jim A. Thomas

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  1. Sumit Kumar Pramanik
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  2. Sreejesh Sreedharan
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  4. Jorge Bernardino de la Serna
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  5. Amitava Das
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  6. Jim A. Thomas
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All authors researched data for and wrote the article. S.K.P., A.D. and J.A.T. discussed the content and reviewed and/or edited the manuscript before submission.

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Correspondence to Amitava Das or Jim A. Thomas.

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Pramanik, S.K., Sreedharan, S., Kandoth, N. et al. Transition metal complexes as optical probes for super-resolution microscopy. Nat Rev Chem 9, 733–748 (2025). https://doi.org/10.1038/s41570-025-00764-w

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