A high-performance electrochemical sensor for biologically meaningful l-cysteine based on a new nanostructured l-cysteine electrocatalyst

Fei Cao; Yikun Huang; Fei Wang; Dongwook Kwak; Qiuchen Dong; Donghui Song; Jie Zeng; Yu Lei

doi:10.1016/j.aca.2018.02.048

A high-performance electrochemical sensor for biologically meaningful l-cysteine based on a new nanostructured l-cysteine electrocatalyst

Anal Chim Acta. 2018 Aug 17:1019:103-110. doi: 10.1016/j.aca.2018.02.048. Epub 2018 Feb 21.

Authors

Fei Cao¹, Yikun Huang², Fei Wang³, Dongwook Kwak⁴, Qiuchen Dong², Donghui Song², Jie Zeng⁵, Yu Lei⁶

Affiliations

¹ Key Laboratory of Biomedical Functional Materials, School of Sciences, China Pharmaceutical University, Nanjing 211198, China; Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269, USA. Electronic address: caofei@cpu.edu.cn.
² Department of Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA.
³ Key Laboratory of Biomedical Functional Materials, School of Sciences, China Pharmaceutical University, Nanjing 211198, China.
⁴ Department of Materials Science and Engineering, University of Connecticut, Storrs, CT 06269, USA.
⁵ State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
⁶ Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269, USA. Electronic address: yu.lei@uconn.edu.

PMID: 29625675
DOI: 10.1016/j.aca.2018.02.048

Abstract

As a new class of l-cysteine electrocatalyst explored in this study, Au/CeO₂ composite nanofibers (CNFs) were employed to modify the screen printed carbon electrode (SPCE) to fabricate a novel l-cysteine (CySH) electrochemical sensor with high performance. Its electrochemical behavior and the roles of Au and CeO₂ in the composite toward electro-oxidation of CySH were elucidated and demonstrated using cyclic voltammetry and amperometry techniques for the first time through the comparison with pure CeO₂ NFs. More specifically, the Au/CeO₂ CNFs modified SPCE possessed greatly enhanced electrocatalytic activity toward CySH oxidation. An ultra high sensitivity of 321 μA mM^-1cm^-2 was obtained, which is almost 2.7 times higher than that of pure CeO₂ NFs, revealing that the presence of Au imposed an important influence on the electrocatalytic activity toward CySH. The detailed reasons on such high performance were also discussed. In addition, the as-prepared sensor showed a low detection limit of 10 nM (signal to noise ratio of 3), a wide linear range up to 200 μM for the determination of CySH, an outstanding reproducibility and good long-term stability, as well as an excellent selectivity against common interferents such as tryptophan, tyrosine, methionine, ascorbic acid and uric acid. All these features indicate that the Au/CeO₂ composite nanofiber is a promising candidate as a new class of l-cysteine electrocatalyst in the development of highly sensitive and selective CySH electrochemical sensor.

Keywords: Au/CeO(2) composite nanofibers; Electrocatalytic oxidation; Electrochemical sensor; Electrospinning; l-cysteine.

MeSH terms

Carbon / chemistry
Catalysis
Cerium / chemistry
Cysteine / analysis*
Electrochemical Techniques*
Electrodes
Gold / chemistry
Particle Size
Surface Properties

Substances

Cerium
ceric oxide
Carbon
Gold
Cysteine