Femtosecond Laser Spectroscopy of the Rhodopsin Photochromic Reaction: A Concept for Ultrafast Optical Molecular Switch Creation (Ultrafast Reversible Photoreaction of Rhodopsin)

Molecules

Olga Smitienko³  Victor Nadtochenko³  Tatiana Feldman³  Maria Balatskaya¹  Ivan Shelaev²  Fedor Gostev²  Oleg Sarkisov²  Mikhail Ostrovsky³ 

[1] Faculty of Basic Medicine, Lomonosov Moscow State University, Lomonosovsky pr. 31/5, Moscow 119192, Russia; E-Mail:;Semenov Institute of Chemical Physics, Russian Academy of Sciences, Kosygin st.4, Moscow 119991, Russia; E-Mails:;Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin st.4, Moscow 119334, Russia; E-Mails:

关键词: rhodopsin;    femtosecond spectroscopy;    coherent reaction;    photoreversibility;    molecular switches;   

DOI  :  10.3390/molecules191118351

来源: mdpi

【 摘 要 】

Ultrafast reverse photoreaction of visual pigment rhodopsin in the femtosecond time range at room temperature is demonstrated. Femtosecond two-pump probe experiments with a time resolution of 25 fs have been performed. The first pump pulse at 500 nm initiated cis-trans photoisomerization of rhodopsin chromophore, 11-cis retinal, which resulted in the formation of the primary ground-state photoproduct within a mere 200 fs. The second pump pulse at 620 nm with a varying delay of 200 to 3750 fs relative to the first pump pulse, initiated the reverse phototransition of the primary photoproduct to rhodopsin. The results of this photoconversion have been observed on the differential spectra obtained after the action of two pump pulses at a time delay of 100 ps. It was found that optical density decreased at 560 nm in the spectral region of bathorhodopsin absorption and increased at 480 nm, where rhodopsin absorbs. Rhodopsin photoswitching efficiency shows oscillations as a function of the time delay between two pump pulses. The quantum yield of reverse photoreaction initiated by the second pump pulse falls within the range 15% ± 1%. The molecular mechanism of the ultrafast reversible photoreaction of visual pigment rhodopsin may be used as a concept for the development of an ultrafast optical molecular switch.

【 授权许可】

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