Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (9): 1787-1794.doi: 10.3866/PKU.WHXB201507241

• PHOTOCHEMISTRY AND RADIATION CHEMISTRY • Previous Articles     Next Articles

Fluorescence Quenching of Eosin Y by Tyrosine

Jing-Dong. WANG,Shuang. LI,Rong. LÜ,An-Chi. YU()   

  • Received:2015-04-17 Published:2015-09-06
  • Supported by:
    the National Natural Science Foundation of China(21373269)

Abstract:

Quenching of a fluorescent probe by amino acid residues can provide valuable information about the structural and conformational dynamics of a biopolymer. Herein, we systematically investigated the ultrafast fluorescence quenching dynamics of Eosin Y in the presence of N-acetyl-tyrosine (AcTyr) in H2O and D2O solutions using both femtosecond transient absorption and time-correlated single-photon counting experiments. We found that the quenching of the fluorescence of Eosin Y by AcTyr in aqueous solution is mainly because of the formation of a ground-state complex between Eosin Y and AcTyr. We also found that the lifetime of the ground-state complex formed between Eosin Y and AcTyr showed a clear kinetic isotope effect, indicating that the quenching of the fluorescence of Eosin Y by AcTyr in aqueous solution is via a proton-coupled electron transfer process.

Key words: Femtosecond transient absorption spectroscopy, Time-correlated single-photon counting, Ground-state complex, Tyrosine quenching, Proton-coupled electron transfer

MSC2000: 

  • O643