An electrochemical sensor based on cellulose nanocrystal for the enantioselective discrimination of chiral amino acids.
A novel electrochemical sensor based on 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanocrystals (TOCNCs) and l-cystines (l-Cys) modified Au electrode (TOCNC/l-Cys/Au) has been fabricated for detection and discrimination of the enantiomers of phenylalanine (Phe), leucine (Leu), and valine (Val). The three amino acids are in connection with metabolism diseases. The TOCNC/l-Cys/Au electrode exhibited obvious peak current difference for the amino acid enantiomers by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The TOCNCs on the electrode surface expressed different interactions with d- and l-amino acids, so the electrochemical recognitions of the three amino acid enantiomers were achieved. TOCNCs were characterized by Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM). The modified electrodes were characterized by SEM and electrochemical techniques. According to DPV, peak currents of the two enantiomers decreased linearly with their concentrations. Furthermore, satisfactory results were obtained when this electrode was applied to measure the d- and l-Phe mixture. The experimental results show that TOCNCs are suitable material for chiral sensor. The contrast of serum sample of healthy people and patients with type 2 diabetes also was proposed, and significant difference was exhibited on the modified electrode. This work is significant for the screening, diagnosis, and treatment of multiple metabolic diseases.
Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China.
Qing
Q
Bi
Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730070, China.
Shuqing
S
Dong
Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730070, China; Graduate University of Chinese Academy of Science, Beijing 100080, China.
Yaming
Y
Sun
Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China. Electronic address: luxq@nwnu.edu.cn.
Xiaoquan
X
Lu
Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730070, China. Electronic address: zhaol@licp.cas.cn.
Liang
L
Zhao
D000596:Amino Acids / Q000032:analysis* / Q000097:blood / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry*; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D055664:Electrochemical Techniques / Q000639:trends; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006801:Humans; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry*; D015203:Reproducibility of Results; D013237:Stereoisomerism
D000596:Amino Acids; D006046:Gold; D002482:Cellulose
Cellulose nanocrystals; Chiral amino acids; Electrochemical sensor; Enantioselective discrimination