Circularly polarized lanthanide luminescence for advanced security inks

Lewis E. MacKenzie, Robert Pal

Research output: Contribution to journalArticlepeer-review


Authenticating products and documents with security inks is vital to global commerce, security and health. Lanthanide complexes are widely used in luminescent security inks owing to their unique and robust photophysical properties. Lanthanide complexes can also be engineered to undergo circularly polarized luminescence (CPL), which encodes chiral molecular fingerprints in luminescence spectra that cannot be decoded by conventional optical measurements. However, chiral CPL signals have not yet been exploited as an extra security layer in advanced security inks. This Review introduces CPL and related concepts that are necessary to appreciate the challenges and potential of lanthanide-based, CPL-active security inks. We describe recent advances in CPL analysis and read-out technologies that have expedited CPL-active security ink applications. Further, we provide a systematic meta-analysis of strongly CPL-active EuIII, TbIII, SmIII, YbIII, CmIII, DyIII and CrIII complexes, discussing the suitability of their photophysical properties and highlighting promising candidates. We conclude by providing key recommendations for the development and advancement of the field.
Original languageEnglish
Pages (from-to)109–124
Number of pages16
JournalNature Reviews Chemistry
Publication statusPublished - 7 Dec 2020


  • coordination chemistry
  • lanthanide luminescence
  • security inks
  • anti-counterfeiting measures
  • luminescent security dyes
  • circularly polarized
  • photophysical properties
  • Lanthanide complexes
  • circularly polarized luminescence (CPL)

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