Department of Biomedical Engineering, Indian Institute of Technology, Hyderabad, 502285, India.
Department of Electrical Engineering, Indian Institute of Technology, Hyderabad, 502285, India.
Mikrochim Acta. 2024 Sep 21;191(10):614. doi: 10.1007/s00604-024-06687-5.
A novel bimetallic Fe/Co-metal-organic framework (MOF) hydrogel-based wearable sweat sensor was developed. Morphological and structural analysis of the hydrogel shows uniformly sized spines and spindle-shaped particles of the Fe/Co-MOF, and it has a high surface area (132.306 m g) and porosity (0.059 cm g) as confirmed by Brunauer-Emmett-Teller (BET) studies. The integration of the bimetallic MOF into a polyvinyl alcohol/chitosan (PVA/CS)-mixed matrix resulted in a multiple network hydrogel. The optimisation study investigated the effects of different pH of the PBS electrolyte, scan rates, and accumulation time in voltammetry. The electrochemical methods such as cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS) provided information on the redox behaviour, electrochemical stability, and catalytic activity of the hydrogel. The sensor demonstrates a wide linear detection range from 0.05 µM to 100 mM, a superior sensitivity of 0.02 mA mM cm, and a lower limit of detection of 0.01 µM . Active sites distributed over the hydrogel surface, specifically Fe and Co within the MOF structure, catalyse the oxidation of L-lactic acid, resulting in electron transfer and the formation of pyruvic acid. Notably, the fabricated sensor exhibits high selectivity, effectively discriminating against interfering species such as uric acid, ascorbic acid, glucose, urea, dopamine, NaCl, and CaCl. Real-time analysis conducted in a simulated sweat sample via the standard addition method resulted in good recovery percentages of a minimum of 98%. The work presented here is a versatile and simple platform for point-of-care testing, especially for athletes and military personnel.
一种新型双金属 Fe/Co-金属有机骨架（MOF）水凝胶基可穿戴汗液传感器被开发出来。水凝胶的形态和结构分析表明，Fe/Co-MOF 具有均匀尺寸的刺和纺锤形颗粒，比表面积（132.306 m g）和孔隙率（0.059 cm g）较高，这是通过 Brunauer-Emmett-Teller（BET）研究证实的。将双金属 MOF 整合到聚乙烯醇/壳聚糖（PVA/CS）混合基质中，形成了一种多重网络水凝胶。优化研究考察了 PBS 电解质不同 pH 值、扫描速率和伏安法中的积累时间的影响。循环伏安法（CV）、方波伏安法（SWV）和电化学阻抗谱（EIS）等电化学方法提供了关于水凝胶的氧化还原行为、电化学稳定性和催化活性的信息。该传感器在 0.05 μM 至 100 mM 的宽线性检测范围内表现出优异的灵敏度（0.02 mA mM cm）和较低的检测限（0.01 μM）。分布在水凝胶表面的活性位点，特别是 MOF 结构内的 Fe 和 Co，催化 L-乳酸的氧化，导致电子转移和丙酮酸的形成。值得注意的是，所制造的传感器表现出高选择性，能够有效区分尿酸、抗坏血酸、葡萄糖、尿素、多巴胺、NaCl 和 CaCl 等干扰物质。通过标准添加法在模拟汗液样本中进行的实时分析导致回收率至少为 98%。本工作为即时检测提供了一个通用且简单的平台，特别是对于运动员和军人。
