A fast, high-affinity fluorescent serotonin biosensor engineered from a tick lipocalin

Nat Methods. 2021 Mar;18(3):258-261. doi: 10.1038/s41592-021-01078-7. Epub 2021 Feb 25.


Serotonin (5-HT) is an important signaling monoamine and neurotransmitter. We report structure-guided engineering of a green fluorescent, genetically encoded serotonin sensor (G-GESS) from a 5-HT-binding lipocalin in the soft tick Argas monolakensis. G-GESS shows fast response kinetics and high affinity, specificity, brightness and photostability. We used G-GESS to image 5-HT dynamics in cultured cells, brain slices and behaving mice.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Retracted Publication

MeSH terms

  • Animals
  • Argas / metabolism
  • Biosensing Techniques / methods*
  • Brain / diagnostic imaging
  • Cell Line
  • HEK293 Cells
  • Humans
  • Lipocalins / metabolism*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Optical Imaging / methods*
  • Serotonin / analysis*


  • Lipocalins
  • Serotonin