Temperature-sensitive electrochemical recognition of tryptophan enantiomers based on β-cyclodextrin self-assembled on poly(L-glutamic acid).
A poly(l-glutamic acid)/β-cyclodextrin (P-l-Glu/β-CD)-modified glassy carbon electrode (GCE) was prepared by electrochemical polymerization of l-glutamic acid on GCE and subsequent self-assembly of β-CD onto the obtained P-l-Glu. Electrochemical recognition of tryptophan (Trp) enantiomers with the P-l-Glu/β-CD was investigated by differential pulse voltammetry (DPV), and the results show that Trp enantiomers can be effectively recognized at the P-l-Glu/β-CD-modified GCE. It is also interesting to find that temperature plays a crucial role in the enantioselective recognition, which is evidenced by the variable-temperature UV spectra of the inclusion complexes of Trp enantiomers and β-CD. Under optimum conditions, the oxidation peak current ratio of l-Trp to d-Trp could reach 2.30, which is attributed to the stereoselectivity of β-CD to the enantiomeric pair of Trp.
Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University , Changzhou 213164, P. R. China.
Yongxin
Y
Tao
Jiangying
J
Dai
Yong
Y
Kong
Yan
Y
Sha
D055664:Electrochemical Techniques; D011099:Polyglutamic Acid / Q000737:chemistry*; D058105:Polymerization; D013237:Stereoisomerism; D013696:Temperature; D014364:Tryptophan / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry*
D047392:beta-Cyclodextrins; D011099:Polyglutamic Acid; D014364:Tryptophan; C031215:betadex