Second-order nonlinear optical properties of fluorescent proteins for second-harmonic imaging

Evelien De Meulenaere, Inge Asselberghs, Marc De Wergifosse, Edith Botek, Stijn Spaepen, Benoît Champagne, Jos Vanderleyden, Koen Clays

Research output: Contribution to journalArticlepeer-review


The second-order nonlinear optical properties of three fluorescent proteins (FPs) (green, EGFP; yellow, EYFP; and red, DsRed) have been experimentally determined by frequency-resolved femtosecond hyper-Rayleigh scattering. As expected, DsRed, with its lower-energy bandgap between ground and excited state, exhibits the largest intrinsic hyperpolarizability. The anomalously low first hyperpolarizability for the yellow variant has been rationalized in terms of the centrosymmetrical arrangement between the phenolic Tyr203 (Tyr = tyrosine) residue and the chromophoric Tyr66 moiety, leaving the small imidazolinone moiety as the only effective non-centrosymmetric chromophore for second-order nonlinear effects. The experimental findings are corroborated by high-level computational results and suggest molecular engineering strategies to produce a full rainbow of FPs with enhanced nonlinear optical properties.

Original languageEnglish
Pages (from-to)7514-7519
Number of pages6
JournalJournal of Materials Chemistry
Issue number40
Publication statusPublished - 28 Oct 2009


Dive into the research topics of 'Second-order nonlinear optical properties of fluorescent proteins for second-harmonic imaging'. Together they form a unique fingerprint.

Cite this