Diabetes is a chronic disease, which is the seventh leading cause of death worldwide. The increased risk to the health of diabetic patients, with comorbidities in harsh situations like COVID-19 pandemics, necessitates real-time monitoring of blood glucose. Monitoring of blood glucose is invasive, hence, sweat glucose monitoring can be an alternative approach to address the invasive issue in blood glucose monitoring. This work reports a facile, low-cost, high-performance copper (Cu) native oxide (CuNOx)-based nonenzymatic electrochemical sensor for sweat glucose sensing. We utilized a very thin Cu native oxide of ~10 nm on Cu thin film for the sensing because of the excellent catalytic oxidation behavior of cuprous oxide (Cu₂O) to glucose. The anodic sweep of cyclic voltammetry of glucose showed that the hydroxyl ions from sodium hydroxide convert the electrode surface into different oxides [Cu(I), Cu(II) Cu(III)], which electro-oxidize glucose to gluconolactone, then eventually to gluconic acid resulting in oxidation current. The CuNOx sensors exhibited a sensitivity of 603.42 μA mM⁻¹ cm⁻², a linear range beyond the desired limit of 7.00 mM with excellent linearity, and a low limit of detection of 94.21 μM. Excellent repeatability and stability (stable >1 year) with relative standard deviation (RSD) of 2.67%, and 2.70%, respectively were achieved for 1 mM glucose. The selectivity with common interferants of glucose in human sweat and blood showed an RSD of 3.56%. We believe the electrocatalytic efficacy of the CuNOx sensors for glucose sensing can open a new prospect in the fabrication of wearable sweat glucose sensors.

糖尿病是一种慢性疾病，是全球第七大死因。糖尿病患者的健康风险增加，在 COVID-19 大流行等恶劣情况下合并症，需要实时监测血糖。血糖监测是侵入性的，因此，汗液葡萄糖监测可以成为解决血糖监测中侵入性问题的替代方法。这项工作报告了一种简便、低成本、高性能的基于铜 (Cu) 天然氧化物 (CuNOx) 的非酶电化学传感器，用于检测汗液葡萄糖。由于氧化亚铜（Cu ₂O) 到葡萄糖。葡萄糖循环伏安法的阳极扫描表明，氢氧化钠中的氢氧根离子将电极表面转化为不同的氧化物 [Cu(I), Cu(II) Cu(III)]，将葡萄糖电氧化为葡萄糖酸内酯，然后最终转化为葡萄糖酸产生氧化电流。CuNOx 传感器的灵敏度为 603.42 μA mM ^-1  cm ^-2，线性范围超出了所需的 7.00 mM 限值，具有出色的线性，检测下限为 94.21 μM。1 mM 葡萄糖的相对标准偏差 (RSD) 分别为 2.67% 和 2.70%，具有出色的重复性和稳定性（稳定 >1 年）。对人体汗液和血液中葡萄糖的常见干扰物的选择性显示出 3.56% 的 RSD。我们相信用于葡萄糖传感的 CuNOx 传感器的电催化功效可以为可穿戴汗液葡萄糖传感器的制造开辟新的前景。