Luo et al. Soft Sci 2024;4:7 DOI: 10.20517/ss.2023.40 Soft Science © The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, sharing, adaptation, distribution and reproduction in any medium or format, for any purpose, even commercially, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. www.oaepublish.com/ss Open Access Research Article Printing surface cuprous oxides featured liquid metal for non-enzymatic electrochemical glucose sensor Yiyao Luo 1,# , Gengcheng Liao 1,# , Zixuan Guo 1 , Zongyu Huang 1,3 , Long Ren 2,* , Xiang Qi 1,* 1 Human Key Laboratory of Micro-Nano Energy Materials and Devices, School of Physics and Optoelectronic, Xiangtan University, Xiangtan 411105, Hunan, China. 2 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, Hubei, China. 3 Human Key Laboratory of Two-dimensional Materials, Hunan University, Changsha 410082, Hunan, China. # Authors contributed equally. * Correspondence to: Prof. Long Ren, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, 122 Luoshi Road, Hongshan District, Wuhan 430070, Hubei, China. E-mail: renlong@whut.edu.cn; Prof. Xiang Qi, Human Key Laboratory of Micro-Nano Energy Materials and Devices, School of Physics and Optoelectronic, Xiangtan University, Xinxiang Road, Xianfeng Street, Yuhu District, Xiangtan 411105, Hunan, China. E-mail: xqi@xtu.edu.cn How to cite this article: Luo Y, Liao G, Guo Z, Huang Z, Ren L, Qi X. Printing surface cuprous oxides featured liquid metal for non- enzymatic electrochemical glucose sensor. Soft Sci 2024;4:7. https://dx.doi.org/10.20517/ss.2023.40 Received: 28 Aug 2023 First Decision: 27 Sep 2023 Revised: 10 Nov 2023 Accepted: 7 Dec 2023 Published: 15 Jan 2024 Academic Editors: Zhifeng Ren, Chuanfei Guo, Wei Rao Copy Editor: Pei-Yun Wang Production Editor: Pei-Yun Wang Abstract Electrochemical glucose sensors that rely on two-dimensional (2D) oxides have attracted significant attention owing to the strong sensing activity of 2D oxides, but their practical application is hindered by the complexity and high cost of fabrication of electrodes and integrated devices. Herein, a convenient and effective fabrication route that includes printing a Ga-based liquid metal (LM) as a current collection electrode, followed by growing electrochemically active 2D oxides directly on the surface of Ga-based LMs under mild conditions, is developed for non-enzyme-based electrochemical sensors. Specifically, 2D annealed Cu-Oxide (ACO) is successfully grown on a printed Ga electrode through a galvanic replacement reaction, resulting in the formation of a mechanically and electrically well-matched interface between the active sensing materials and the current collection substrate. Benefitting from the high quantity of 2D ACO and good charge transfer at the interface, the as-prepared ACO electrode exhibits attractive glucose sensing performance, with a wide linear range (1 μM-10 mM) of effective detection, low detection limit down to 1 μM, and high sensitivity of 0.87 μA·mM -1 ·cm -2 . Our study highlights the potential of using LMs in bio-sensing applications and provides a non-enzyme-based electrochemical biosensor platform for effective glucose detection in diets and clinical diagnostic settings. Keywords: Glucose sensor, liquid metal, cuprous oxide, printing biosensors