Short communicationPotato starch as a highly enantioselective system for temperature-dependent electrochemical recognition of tryptophan isomers
Graphical abstract
Due to the favorability of intermolecular H-bonds formation between PS and D-Trp, the PS-based enantioselective system exhibits higher affinity for D-Trp than L-Trp, and therefore effective electrochemical recognition of Trp isomers is achieved successfully.
Section snippets
1. Introduction
Chiral recognition of isomers is of significant importance in the living world because the body is amazingly enantioselective, showing different physiological responses to different isomers [1]. Recent years have witnessed the development of supramolecular chemistry-based chiral recognition [2], in which the host–guest interactions are utilized for distinguishing between the left- and right-handed forms of chiral compounds. More recently, the combination of electrochemistry and supramolecular
2.1. Reagents and apparatus
Potato starch (PS) was obtained from Aladdin Chemistry Co., Ltd. (Shanghai, China). Hydroxypropyl potato starch (H-PS) was purchased from Shanghai Guomin Starch Industry Co., Ltd. (China). Electrochemical experiments were conducted on a CHI-660D electrochemical workstation (Shanghai Chenhua Instruments Co., China) in a traditional three-electrode system. The working electrode was a glassy carbon electrode modified with PS or H-PS self-assembled P-l-Glu. The counter electrode was a platinum foil
3.1. Electrochemical characterization of PS and H-PS self-assembled P-l-Glu/GCE
Fig. 1B shows the cyclic voltammograms (CVs) of the electrodes obtained at different stages in 25 mL 0.1 M KCl containing 5 mM Fe(CN)64 −/3 −, and a pair of well-defined redox peaks is observed at the bare GCE (curve a). After P-l-Glu is electrodeposited onto GCE, the peak current (Ip) is increased (curve b). The improved electrochemical reversibility is attributed to the introduced P-l-Glu films, which can accelerate the charge transfer and facilitate the transition between the redox probe couple
4. Conclusions
PS is self-assembled onto P-l-Glu via H-bonds and used as a chiral sensing platform for the recognition of Trp isomer. Due to the favorability of intermolecular H-bonds formation between PS and d-Trp, the PS-based enantioselective system exhibits higher affinity for d-Trp than l-Trp, and therefore effective electrochemical recognition of Trp isomers is achieved successfully. Interestingly, the recognition efficiency is significantly decreased at the H-PS-based chiral sensing system, which is
Acknowledgments
This work was supported by NSFC (21275023, 11532003), Graduate Research Innovation Program for Universities of Jiangsu Province (SJLX15_0535), and PAPD.
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