A single-atom Cu-N2 catalyst eliminates oxygen interference for electrochemical sensing of hydrogen peroxide in a living animal brain

Xiaolong Gao; Wenjie Ma; Junjie Mao; Chun-Ting He; Wenliang Ji; Zheng Chen; Wenxing Chen; Wenjie Wu; Ping Yu; Lanqun Mao

doi:10.1039/d1sc04755h

A single-atom Cu-N₂ catalyst eliminates oxygen interference for electrochemical sensing of hydrogen peroxide in a living animal brain

Chem Sci. 2021 Nov 2;12(45):15045-15053. doi: 10.1039/d1sc04755h. eCollection 2021 Nov 24.

Authors

Xiaolong Gao^{1

2}, Wenjie Ma^{1

2}, Junjie Mao³, Chun-Ting He⁴, Wenliang Ji¹, Zheng Chen³, Wenxing Chen⁵, Wenjie Wu¹, Ping Yu^{1

2}, Lanqun Mao^{1

6

2}

Affiliations

¹ Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, The Chinese Academy of Sciences (CAS) Beijing 100190 China lqmao@bnu.edu.cn.
² University of Chinese Academy of Sciences Beijing 100049 China.
³ Key Laboratory of Functional Molecular Solids, Ministry of Education, College of Chemistry and Materials Science, Anhui Normal University Wuhu 241002 China.
⁴ MOE Key Laboratory of Functional Small Organic Molecule, College of Chemistry and Chemical Engineering, Jiangxi Normal University Nanchang 330022 China.
⁵ Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications, School of Materials Science and Engineering, Beijing Institute of Technology Beijing 100081 China.
⁶ College of Chemistry, Beijing Normal University Xinjiekouwai Street 19 Beijing 100875 China.

Abstract

Hydrogen peroxide (H₂O₂) plays essential roles in various physiological and pathological processes. The electrochemical hydrogen peroxide reduction reaction (HPRR) has been recognized as an efficient approach to H₂O₂ sensing; however, the HPRR has always suffered from low tolerance against the oxygen reduction reaction (ORR), resulting in poor selectivity of the HPRR-based sensing platform. In this study, we find that the electrochemical HPRR occurs preferentially compared to the ORR when isolated Cu atoms anchored on carbon nitride (Cu₁/C₃N₄) are used as a single-atom electrocatalyst, which is theoretically attributed to the lower energy barrier of the HPRR than that of the ORR on a Cu₁/C₃N₄ single-atom catalyst (SAC). With the Cu₁/C₃N₄ SAC as the electrocatalyst, we fabricated microsensors that have a good response to H₂O₂, but not to O₂ or other electroactive neurochemicals. When implanted into a living rat brain, the microsensor shows excellent in vivo sensing performance, enabling its application in real-time quantitative investigation of the dynamics of H₂O₂ production induced by mercaptosuccinate and glutathione monoethyl ester in a living animal brain.