Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon 16419, Korea.
Graduate Program in Nursing, Universidade do Vale do Rio dos Sinos, 93022-750 São Leopoldo, Brazil.
Sensors (Basel). 2021 Mar 6;21(5):1852. doi: 10.3390/s21051852.
Lactate is an important organic molecule that is produced in excess during anaerobic metabolism when oxygen is absent in the human organism. The concentration of this substance in the body can be related to several medical conditions, such as hemorrhage, respiratory failure, and ischemia. Herein, we describe a graphene-based lactate biosensor to detect the concentrations of L-lactic acid in different fluids (buffer solution and plasma). The active surface (graphene) of the device was functionalized with lactate dehydrogenase enzyme using different substances (Nafion, chitosan, and glutaraldehyde) to guarantee stability and increase selectivity. The devices presented linear responses for the concentration ranges tested in the different fluids. An interference study was performed using ascorbic acid, uric acid, and glucose, and there was a minimum variation in the Dirac point voltage during detection of lactate in any of the samples. The stability of the devices was verified at up to 50 days while kept in a dry box at room temperature, and device operation was stable until 12 days. This study demonstrated graphene performance to monitor L-lactic acid production in human samples, indicating that this material can be implemented in more simple and low-cost devices, such as flexible sensors, for point-of-care applications.
乳酸是一种重要的有机分子，当人体缺氧时，它会在无氧代谢过程中过量产生。该物质在体内的浓度与多种医学病症相关，如出血、呼吸衰竭和缺血。在此，我们描述了一种基于石墨烯的乳酸生物传感器，用于检测不同液体（缓冲溶液和血浆）中 L-乳酸的浓度。该设备的活性表面（石墨烯）使用不同的物质（Nafion、壳聚糖和戊二醛）进行了乳酸脱氢酶的功能化，以保证稳定性和提高选择性。该设备在不同液体的测试浓度范围内呈现出线性响应。使用抗坏血酸、尿酸和葡萄糖进行了干扰研究，在任何样品中检测乳酸时，狄拉克点电压的变化最小。在室温下的干燥箱中保存长达 50 天，可验证设备的稳定性，并且设备运行稳定，最长可达 12 天。该研究证明了石墨烯在监测人体样本中 L-乳酸产生方面的性能，表明该材料可用于更简单、成本更低的设备，如用于即时护理应用的柔性传感器。
